Red Shirts disrupt city rail

Thailand's anti-government Red Shirts threw tyres onto elevated city rail tracks on Tuesday in a bid to thwart a feared military crackdown as the government talked tough against the protesters.

The Reds said they would turn up the heat on Prime Minister Abhisit Vejjajiva as they beefed up their defences, planning an appeal on Wednesday to persuade more people to join their mass rally in the capital.

Bangkok's Skytrain was halted for several hours after Reds laid tyres on the rails at a station above the protest site to stop troops using it for a possible surprise attack, forcing many commuters to walk to work.

Soldiers with guns were guarding the capital, which is under a state of emergency and has been rocked by the worst political unrest for almost two decades, with 26 people killed and almost 1000 injured this month.

The government said it would not tolerate roadblocks set up by the protesters - who have been staging weeks of rolling rallies to campaign for immediate elections - to prevent troop reinforcements heading to the capital.

"The government has intensified measures against protesters because they have created a situation of unrest by setting up checkpoints which violate other people's rights," Deputy Prime Minister Suthep Thaugsuban told reporters.

"We cannot talk to these people any longer," he said.

Abhisit, regarded as elitist and undemocratic by his opponents, said his government was striving to find a political solution to the crisis, but he warned it would take time.

"We will try to enforce the law with minimum losses and we will try to find a political resolution, but it takes time, patience and cooperation," he said in an interview with CNN.

Abhisit has rejected an offer by the Reds to disperse if elections are held in three months' time.

A day after Thailand's revered king spoke of the need for peace in his first public remarks since the crisis began, protesters remained on high alert for a crackdown by security forces.

The Red Shirts have reinforced their roadblocks and stepped up security checks on the perimeter of their sprawling protest site, which has been fortified with barricades made from piles of truck tyres and bamboo stakes.

"Each passing day will make us stronger. At least we can hold government forces at bay for another day," said a Reds leader, Jatuporn Prompan.

King Bhumibol Adulyadej spoke on national television on Monday for the first time since the protests broke out in mid-March, addressing a group of newly appointed judges, but he did not directly mention the political crisis.

"Do your job with honesty. In this country there may be some people who forget their duty. You should be an example by working honestly and properly, your job is very important," the king said.

"It will help the country to live in peace and contentment," the ailing 82-year-old told the judges at the Bangkok hospital where he has been since September.

Thailand's opposition has asked for an audience with the king, who has intervened in previous bouts of civil unrest.

The government has said it has uncovered a network of people suspected of plotting to overthrow the kingdom's revered monarchy and will issue summons, and possibly arrest warrants, for alleged members.

"The government will not allow these people to insult the monarchy," Suthep said. "If necessary we will bar all of them from leaving Thailand."

The Reds denied they were involved in any attempt to undermine the royals and threatened to sue the government over the accusation.

"This is the government's way of using its imagination to crush opponents," said protest leader Nattawut Saikuar.

The Reds are mostly supporters of ex-premier Thaksin Shinawatra, who was ousted in a 2006 coup and now lives overseas to avoid a jail term for corruption.

Thaksin, who was in Montenegro at the weekend, said he had been in contact with the opposition protesters in Thailand.

"We just fight for democracy," he told reporters in the Adriatic republic.