In addition, Lebanon's Justice Minister said that Israel's raid of his country could "sabotage" the already shaky truce, and give Hezbollah militants an excuse not to disarm.
Like the UN, he warned that Israel’s raid on eastern Lebanon on Saturday could further rattle foreign nations being called upon to sign up to a beefed-up UN force on the border.
In relation to the ceasefire, Lebanon’s Defence Minister Elias Murr said: "Any violation ... any rocket that would give Israel a justification (to hit Lebanon) will be treated harshly. It will be considered as direct collaboration with the Israeli enemy," he said, adding that those responsible "will be tried and referred to a military tribunal."
The Shiite Muslim Hezbollah fired more than 4,000 rockets across the border during the 34-day war, killing 41 civilians, but none have landed in Israel since the ceasefire came into effect on Monday.
Mr Murr said Hezbollah "is totally committed to this, so there are no fears."
'Israel trying to sabotage ceasefire'
In relation to Israel’s raid on Saturday, Lebanon's Justice Minister Charles Rizk told CNN: "When you have some actions as the Israeli raid the other day, this really gives a very bad sign to the European or to outside forces ... and makes them shy, as matter of fact, to expose their soldiers to this”.
Mr Rizk said the "very unfortunate action" by the Israelis "took place as if it was to sabotage this process," adding that Israel's actions also "give an alibi for Hezbollah to stop talking about disarming."
Israeli officials remained defiant however, warning that it would keep up raids against Hezbollah to prevent the Shiite militia from getting weapons to prepare for the "next round" of war.
Top UN envoy Terje Roed-Larsen said Israel's raid deep inside Lebanon on Saturday would "not exactly give incentives" for countries to contribute to the UN peacekeeping forces.
UN Security Council Resolution 1701 that led to the ceasefire calls for Israeli troops to withdraw from south Lebanon in tandem with the deployment of the Lebanese army and a strengthened UN force of 15,000 troops and the disarmament of Hezbollah.
Israeli Defense Minister Amir Peretz says his soldiers will prevent the Lebanese army from deploying in areas of southern Lebanon currently held by Israeli troops until the arrival of troops to boost the existing international force.
'Truce may unravel': UN
A day after it condemned an Israeli raid on the guerrillas in Lebanon as a violation, the UN said the week-old truce between Israel and Hezbollah could easily collapse.
Mr Roed-Larsen said the truce that halted the 34-day war had provided the Lebanese government with a good chance to extend its authority over all of the country.
"We also do believe that unfortunately there is a tilting edge where things very easily, within the next weeks or months, can slide out of control," Mr Roed-Larsen said in Beirut.
"This is why it's so important that all parties concerned exercise utmost restraint in this situation in order to give the Lebanese army the possibility of deploying fully along all borders of Lebanon, and particularly in the south, and also to allow the international community to provide troops."
A 30,000-strong force is envisaged for south Lebanon, made up of Lebanese and UN troops in equal number.
Israeli blockade 'unhelpful': UN
Mr Roed-Larsen also said Israel's blockade of Lebanon was "unhelpful" to conditions in the country. Israel implemented the air, sea and land blockade when hostilities broke out with the Lebanese Shiite militia Hezbollah on July 12, and it remains in place despite a ceasefire that took effect on August 14.
The Gulf Cooperation Council last week strongly condemned the blockade because it prevents the work of relief services, while the EU demanded an end to Israel's action because it has "very bad consequences" for the Lebanese people.
Israel, however, has said the blockade only aims to stop Hezbollah from smuggling arms into Lebanon.
'Some troops not welcome': Israel
The UN has been urging countries, particularly European nations, to send troops to a planned 15,000-strong peacekeeping force, but most governments want more details on the precise mandate of the force before contributing.
France said it had asked EU president Finland to call a meeting of the bloc's member states to discuss Lebanon. A Finnish official said the EU's political and security committee would meet on Wednesday.
Israel says Italy should play a key role in peacekeeping in southern Lebanon, while other countries' troops are not welcome.
"It is important that the multinational force arrives in the region as quickly as possible and that Italy is a fundamental part of it," Israeli premier Ehud Olmert said during a telephone conversation with Italian Prime Minister Romano Prodi.
Mr Olmert also expressed hope that Turkey will contribute troops to the international force after a meeting with Turkish Foreign Minister Abdullah Gul.
But another government statement said that others were not welcome in the force.
"Israel doesn't want to see within the multinational force soldiers from countries whose governments supported Hezbollah," said a statement following the weekly security cabinet's meeting.
"Israel is opposed to the participation in the mulinational force of contingents from states with which it has no (diplomatic) relations," Mr Olmert was quoted as saying on the Yediot Aharonot newspaper website.
Israel's UN ambassador Dan Gillerman and Foreign Minister Tzipi Livni have both said it would be difficult to accept participation in the UN force of countries that have no relations with Israel, such as Malaysia and Indonesia.
Arab foreign ministers
Meanwhile 18 Arab League foreign ministers have said they are committed to help reconstruction efforts in Lebanon but have delayed concrete plans to a meeting of Arab finance ministers in September.
After the emergency meeting in Cairo, Kuwaiti foreign minister Sheikh Mohammed Al Sabah said his government planned to donate $US800 million to Lebanon, while Saudi Arabia said it had already donated $US500 million. Other oil-rich nations have also pledged to make donations.
In a bid to defuse Mideast tensions amid rising discord between moderate Arabs and Syria, the diplomats also said Arabs wanted to counter a flood of money that is believed to be coming from Teheran to Hezbollah to finance reconstruction projects.
Hezbollah leader Sheikh Hassan Nasrallah has pledged to help rebuild Lebanon, but has not said where the money will come from, but Iran has denied claims that it has opened its treasury for the rebuilding program.
In a sign of growing regional tensions, Syrian minister Walid Moallem was absent from the meeting. His absence came after many Arab governments were angered by a speech on Tuesday by Syrian President Bashar Assad, who criticised fellow Arab leaders for not supporting Hezbollah.
In other news:
- Israeli reconnaissance planes flew over Lebanon Sunday. Witnesses and Lebanese security sources said high-altitude flights covered virtually the whole country, from its war-torn south to close to the border with Syria in the north and east.
- In Jerusalem, Israel's top general, Lieutenant-General Dan Halutz, told the Israeli cabinet his army had failed to destroy Hezbollah during the war, which claimed 1,183 lives in Lebanon and 157 in Israel.
- Lebanese Prime Minister Fouad Siniora inspected damage in Beirut's southern suburbs, a Hezbollah stronghold ravaged by Israeli air strikes, calling it “a crime against humanity committed by Israel”.
- Iran said it was working on an aid package to help rebuild shattered areas of Lebanon, but a senior foreign ministry official said nothing had yet been decided.
- Israel Radio said Israeli soldiers shot dead a Palestinian and wounded at least two others Sunday at a checkpoint in the occupied West Bank.