Israel has so far ruled out any swap either for the two soldiers held by Hezbollah or another servicemen who was captured last month by Palestinian militants in the

Gaza Strip, triggering a similar offensive.

On Saturday, Israel had pounded television transmission stations and mobile telephone masts in raids across the country that left five dead, including a television station employee.

Britain's junior foreign office minister Kim Howells made London's most unequivocal criticism yet of Israel's offensive, in stark contrast to the line taken by Washington.

"These are not surgical strikes. It's very difficult to understand the kind of military tactics that are being used," Howells said in Beirut.

"If they are chasing Hezbollah, then go for Hezbollah. You don't go for the entire Lebanese nation," he said. "I very much hope that the Americans understand what's happening to Lebanon -- the destruction of the infrastructure, the death of so many children and so many people."

Israel said it opened a 50-mile-long and five-mile-wide (80-kilometre by eight-kilometre) safe passage to Beirut for ships and aircraft, a humanitarian corridor to allow aid to the Lebanese.

Israel's air and sea blockade put Lebanon's only international airport out of action, and the bombing of houses, roads, bridges, factories, warehouses and trucks created scenes reminiscent of the 1975-1990 civil war.

But US President George W. Bush maintained his backing for Israel's campaign as Rice prepared travel to the region in search of what she described as a long-term solution.

"I believe sovereign nations have the right to defend their people from terrorist attack, and to take the necessary action to prevent those attacks," Bush said in his weekly radio address.

Underlining the repercussions of the conflict on the whole region, he said Syria was "a primary sponsor" of Hezbollah and has given the militia Iranian-made weapons.

Syrian Deputy Foreign Minister Faisal Mukdad has said Damascus is ready to open a "dialogue" with the United States to resolve the crisis.

Foreign governments also continued to evacuate their citizens, mainly to the neighbouring island of Cyprus which is battling to find temporary accommodation and flights for the estimated 70,000 evacuees at the height of its holiday season.