Lahore, the capital of Pakistan's Punjab province, we're here to meet a man who is part of a hidden army. We've come to the outskirts of Lahore and we are trying to find our contact. It's getting a little bit dark now - we are still OK but we do have to be a bit cautious because militants in Pakistan have kidnapped foreigners before. These guys say that they can guarantee our safety but the sooner we see them the better.

The man we're here to meet was a member of Lashkar-e-Taiba, "The Army of the Righteous". Even in Pakistan it's a banned terrorist organisation, the group blamed for Mumbai and a string of deadly attacks in India.

So, we have come this rather poor suburb, a rather narrow alleyway in a poor suburb of Lahore to meet these guys - just trying to be as quick as possible -it's best we don't stay here too long. So, we will try and spend about 30 minutes with them and then we will leave.  Asadullah told me he'd been in Lashkar-e-Taiba for 10 years, fighting Indian forces in Kashmir. Asadullah's past means he now prefers to stay anonymous.

ASADULLAH (Translation): I was with about 26 friends... Almost everyone died. I was the only one who survived.

REPORTER: They went on two major missions. In those missions, he personally killed an Indian major and in the other mission he killed three Indian soldiers, and he said while of course it was very difficult over there it is the blessing of God that he survived and came back.

In the 10 years that he fought for them, Lashkar-e-Taiba moved from simply fighting in Kashmir to launching attacks in India.

ASADULLAH (Translation):  The Kashmir problem was left behind by England. It was their doing and they must find a solution.

Lashkar's raids in India, culminating in the Mumbai attacks, means that it's banned, even in Pakistan. But the UN and US say they are simply operating here under a new name - Jamaat-ud-Dawa.  This was Jamaat-ud-Dawa's first public gathering since the attack on Mumbai. India has accused its leader of being the mastermind and security was tight. Yet the organisation claims it is nothing more than an Islamic charity, and denies it is a front for Lashkar-e-Taiba. For a charitable organisation, we were surprised by its violent rhetoric.

MAULANA ABDUL AZIZ, JUD SENIOR LEADER (Translation): Kashmiris are brothers with Pakistanis. Pakistan's relationship with the Kashmiri people is such that Pakistanis will mix their blood with Kashmiris' to prove they are the

One of the senior leaders of the JUD, Maulana Abdul Aziz, issued a call to arms.

MAULANA ABDUL AZIZ (Translation):  By the grace of Allah, the Kashmiris will fight to the end, to the last Indian soldier, and till Kashmir is free by the grace of Allah.

The message from the stage was that Muslims could not rely on outside help to win Kashmir's independence. Another speaker told the crowd it was a religious duty to struggle and fight for Kashmir.

SPEAKER (Translation): My friends and colleagues, from this viewpoint, we have jihad through money, jihad through the media, jihad through preaching, and when the time comes you will kill and be killed.

We drove back to Lahore and found the city in lock-down.  We were told that a number of Islamist groups, such as the Pakistani Taliban, had attacked government and Western targets. I wanted to find out more about whether the Jamaat-ud-Dawa leaders I had seen at the rally were the charity workers they claimed to be or frontmen for the terrorist organisation, Lashkar-e-Taiba.

To try and understand a little bit more about what this group is really all about, and what they do, we have to one of the most authoritative writers here in the country, Ahmed Rashid.  So, obviously writing about these issues in Pakistan can be dangerous, and this is something that is quite new - the level of security here.

REPORTER: The Lashkar-e-Taiba, which was banned, I believe, in Pakistan, and has been blamed for Mumbai, are they one and the same thing as Jamaat-ud-Dawa, because they claim they are not?

AHMED RASHID, AUTHOR AND JOURNALIST: The issue is that every time pressure has come upon them since 2002, they have changed their name. They have closed one office, opened another office, closed one bank account, opened another bank account. So, there has been this shell game of subterfuge and reappearance and then going underground again, and then reappearing in a new light and now, of course, they say they are totally an Islamic charity. But the fact of the matter is that they are still very active politically, they still call for jihad against India - they call for jihad against Kashmir. Now, I mean, you wouldn't be doing that if you were just a charity. You would be talking about saving people's souls rather than going out and having this militant ideology.

REPORTER:  So Lashkar-e-Taiba and Jamaat-ud-Dawa are the same thing?

AHMED RASHID:  Oh, certainly. I mean, I think after Mumbai, for example, there was again a pressure on them. They were told to close their offices. Everyone here still calls them Lashkar-e-Taiba because that's what they are.

Jamaat-ud-Dawa generally shuns all Western media attention. But after difficult negotiations through a local contact, we get word that we've been granted access. We are about an hour outside Lahore, and deep in the countryside here. It's a very typically poor country village - poverty everywhere. We were nervous about how we would be received.

Once this was a military training camp for the banned Lashkar-e-Taiba but now it is the headquarters of Jamaat-ud-Dawa. The base looked more like a military compound than a charity office. They are a bit jumpy about us filming. We just have to be a bit careful about this - access for a TV crew is very rare here.  My initial impressions are on my left-hand side there's a new hospital, here, there is what looks like a school for young men, or even a hostel potentially - it's very much the feeling of a city, or a town within a town, completely walled off and their own facilities and tight security on the outside.

If the UN was right about JUD, we were now inside the nerve centre of one of the world's most dangerous terrorist networks.  Senior members of Jamaat-ud-Dawa had decided they wanted to give us a tour to show the charitable work they do here. Our guides told us they offered medical care to thousands of villagers. We met Riaz Ahmed, who told us he'd brought his 4-year-old daughter Zainab here for treatment for a chest infection.  Riaz said he'd come here because it was cheaper than any alternative.

REPORTER: Can I ask why you have come to this facility and not to a government clinic?

RAIZ AHMED (Translation): Any medication will cost another 400 rupees. We can't afford it. With a slip, we can get medication for 3 or 4 rupees.

He told me that Jamaat-ud-Dawa was helping many people here and wasn't doing anything wrong.

RAIZ AHMED (Translation):  If the Jamaat closes, it won't be good for us. Now the children are at school. Otherwise they'd be doing nothing. They'd misbehave.

Chief spokesman Yahya Mujahid told me the supplies were donated by supportive businesses from across Pakistan. The facilities were clearly well resourced.

REPORTER:  Who pays for this? How do you get the money to buy this?

YAHYA MUJAHID, CHIEF SPOKESMAN (Translation): People from different companies send their samples and that's how we get it. People think it comes from a charity.

It was clear that JUD was attracting a lot of money. Security experts claim that this facility is used to raise funds that are then channelled into terrorism. The JUD deny this. Jamaat-ud-Dawa maintain donations are spent on facilities like this.

REPORTER:  How does this compare to the nearest government operating theatre?

GOVT ADMINISTRATOR: Almost the same.

REPORTER:   And how far is the nearest government..? Far away.

HOMAYOUN BABA: So you see we are serving….. Please convey our message to the world, we are serving Insha'Allah. We are nothing to do anything here.

REPORTER:  Nothing to do what?

HOMAYOUN BABA: Nothing to do anything…

GOVT ADMINISTRATOR: Any illegal activity.

It was clear our escorts were aware of how they were perceived by outsiders. We were taken to the compound school where they teach more than 400 young men. Jamaat-ud-Dawa were keen to stress that the children here are taught the state curriculum but they are accused of using their schools to radicalise and recruit.

REPORTER: Its OK, you can keep the study going.

ESCORT: If you will see, you can observe that this is related to the modern educational techniques - Modern educational techniques?

REPORTER: The planets! And what's this one?

ESCORT: Mosque, this is a mosque.

We were shown the posters you'd see in any classroom. But among them was one condemning the occupation of Muslim lands by Israel and the West. Although the JUD members were keen to keep things focused on their charity work, we wanted to hear their response to allegations that this was a terrorist base. The fact that the UN and the US listed the Jamaat-ud-Dawa as a front for terrorist activities - The fact that India accused Lashkar-e-Taiba of the attack in Mumbai, I mean why would they do that if there is no evidence against you?

YAHYA MUJAH (Translation): India always tried to link Jamaat-ud-Dawa with Lashkar-e-Taiba. But Lashkar-e-Taiba only operates in occupied Kashmir and uses its own name, not any other name. The international media confuse the two and think they're the same.

The longer we stayed, the more unwelcome we felt. Yahya told us some members were not happy about us filming. Yahya seemed to be getting worried. He said we should continue our tour by car. But the mood had changed. Suddenly we realised that we were being escorted off the base. The tour was over.

REPORTER: Oh, so are we leaving now?

The spokesman told us that he could no longer guarantee our safety. He's saying there are some people in here who don't like being filmed and they don't like us filming in this place, so he is saying we should now finish and leave. It seemed the JUD preferred to be left alone and did not welcome outside interference. We returned to Lahore.

I wanted to know why, when the rest of the world says Jamaat-ud-Dawa are a front for terrorism, the Pakistani Government tolerate them. Rana Sanaullah Khan is the Punjab's Law Minister.

REPORTER: I ask about the Jamaat-ud-Dawa because the international attention is on them - are they the same group as Lashkar-e-Taiba?

RANA SANAULLAH KHAN, PUNJAB LAW MINISTER: Yes. There is Jamaat-ud-Dawa.

To my surprise, the minister agreed that although many people in Jamaat-ud-Dawa do good work, it was not just a charity.

RANA SANAULLAH KHAN: Jamaat-ud-Dawa people are doing these terrorist activities in Kashmir and they said this openly, they say this is the war of liberation, this is war of independence, war for Islam.

REPORTER: The Jamaat-ud-Dawa organisation is still there, it is still collecting money, its still there, why is that?

RANA SANAULLAH KHAN:  If only 1,000 people ..

The minister feared that if JUD was closed it would respond with a wave of suicide attacks.

REPORTER:  But is that why the Punjab government doesn't close down Jamaat-ud-Dawa, because of that strength of feeling?

RANA SANAULLAH KHAN: No, no we have closed down there - everything.

REPORTER: But they are still running, the organisation is still there - that's the thing I don't quite understand - even though they are under your administration.

RANA SANAULLAH KHAN: No, no, no they are not running anything, any office as Jamaat-ud-Dawa they are not running any school as Jamaat-ud-Dawa or hospital as Jamaat-ud-Dawa - if the hospital is there and 100 people are giving their 10,000 rupee per month, and the people are benefiting there in the shape of medicine, what need for closing that.

The Minister had accepted that the JUD was more than a charity. However, it was clear that WWWopular support for the organisation meant that it was untouchable, whatever the outside world might say.

AHMED RASHID: The process of demobilising an organisation like this would be very complicated, and very difficult to do, but it would have to be done in a peaceful way. Because if you did it in an aggressive way, as a police or military action, you would be riling up hundreds of thousands of people - people who donate to them, people who have been educated by them, people who benefited from their hospital, or whatever.

We wanted to see how much popular support they had here in the city. It was Friday, and we headed for the group's main mosque. We've noticed that half the road is blocked off, there's security everywhere, this is for Friday prayers, because they are worried about attack and increased security. We've got to be very careful about how we film this, though. We approached to ask permission to film, and were immediately surrounded by JUD security. One young man asked if we were working for American intelligence.

We have been given five minutes to film the entrance of the main Jamaat-ud-Dawa mosque here, and we are trying to negotiate further access, but it's very tense.

Spokesman Yahya Mujahid, who we'd met at the headquarters, arrived. He told us many people here didn't want to be filmed for religious reasons, but they were also scared of attack, and suspicious of strangers. He was keen to show the size of their following.

I've been told by the spokesman that we should shoot here to show the number of motorcycles, the number of people coming to Friday prayers here at the main Jamaat-ud-Dawa mosque. He says on good days, they can have up to 10,000 people. He says the message is one of follow Islam, follow it strictly, do the right thing, don't do anything illegal. Although the government had told us that they were closely monitoring JUD, here, the police seemed to be protecting them.

Pakistan's Inter-Services Intelligence agency, the ISI, helped set up many of the groups that have fought and supported Pakistan's struggle to regain Kashmir,  groups such as JUD maintain many sympathisers within the military. We got a call from the local journalist we'd been working with wanting to meet us urgently at our hotel.

Our fixer has just had a call from a friend saying that the Inter-Services Intelligence agency, which is the military-run secret service here, a very powerful organisation in Pakistan, has been asking about him. They want more personal details about who he is, what he is doing, why he is working with us, what we are trying to do, exactly what our project is. He said he is worried, mainly because journalists have gone missing here in the past. If you do something that the ISI doesn't like, they can bring you in, you can be interrogated, and in the past, people have disappeared.

We arranged to meet the former ISI chief, who was responsible for setting up many of Pakistan's militant groups. Hamid Gul is now retired, but remains actively involved in the struggle for Kashmir.

REPORTER: These Pakistanis militant groups at the moment, they have received state help and sponsorship and support for and on behalf of the West in the past, but what is the situation now?

HAMID GUL: No Pakistan officially did not support them at all - they were not blocked either because there was a whole lot of free world support for them.

Gul believes that if Islamic militants defeated the West in neighbouring Afghanistan, a new wave of radicalised fighters would turn their attention to Kashmir.

REPORTER: While Kashmir remains in the status it is in right now, what is the immediate future in terms of Pakistanis who might want to go and fight there?

HAMID GUL: I tell you the situation is simply awaiting the resolution of the Afghan conflict once this happens and the Indians don't come to their senses Pakistan and India both will be in trouble.

REPORTER: What do you mean?

HAMID GUL: I mean, if Pakistan resists the jihadis then there will be a problem because then a huge victory would have fallen in the lap of the jihadis and this is bound to have a very profound effect there will be uprising in Kashmir, massive uprising. Maybe it will lead to an armed conflict between the two countries - and then the jihadis will be the right arm of the Pakistan army!

ALL CHANT: Pakistan! Pakistan!

We had heard stark warnings that any attempt to crush groups like Jamaat-ud-Dawa would create a popular backlash. It could lead to all-out war over Kashmir and could even draw the West into what has been, til now, a regional conflict. We went to a large rally in support of Kashmir, part organised by Jamaat-ud-Dawa.

All the banners are saying that Kashmir will be part of Pakistan, that it is the jugular of Pakistan, that it will never let it go, it will be part of our country and it must be resolved through a UN resolution.

The UN has passed a resolution calling for self-determination in Kashmir, but India has so far failed to implement it. Whether LET and JUD are the same organisation is perhaps beside the point. The fact is their members are pursuing the same goal, and if they continue to feel that the West is siding with India, it will become a target. With the increased radicalisation that has swept the region as a result of the war in Afghanistan, and the advent of global jihad, there will be no shortage of new recruits.