Using radio broadcasts and text messages to local officials, the Israelis told the remaining inhabitants to move above the Litani river, about 25 miles north of the Israeli border.

Israeli troops have already mounted cross-border attacks against Hezbollah targets, and suffered several casualties in a firefight with Hezbollah fighters near Avivim yesterday. Israel said that two of its soldiers had died. Last night two Israeli Apache helicopters collided south of the Lebanese border, seriously injuring five crewmen, Israeli media reported.

A quarter of a million people usually live in area targeted by Israel in Lebanon. Up to 60 per cent have already fled after nine days of shelling and air strikes, but the Israeli order sent hundreds more streaming north from the city of Tyre.

About 800 foreigners were evacuated by sea, leaving Tyre’s remaining inhabitants fearing the worst. “The foreigners have gone. That means the war will really begin now,” said Hassan Bazzi, a port worker. Amir Peretz, Israel’s Defence Secretary, said that a full-scale ground attack to stop Hezbollah rockets was an option. “Let no terror organisation feel we would cower from any operation,” he said. “We have no intention of conquering Lebanon but if we have to act to complete our tasks and reach a victory we will do it.”

The British Government was urgently drawing up plans to rescue 86 Britons trapped in the south. “We’re very concerned about the safety of these British nationals,” an official said.

Ehud Olmert, the Israeli Prime Minister, faces domestic pressure to do more, with commentators complaining that a week of airstrikes has failed to stop Hezbollah’s rockets. “You can’t sort the problem out from the air. The only way to solve it is on the ground,” one military analyst told The Times.

The Israelis also know that they must crush Hezbollah before world opinion demands an end to the fighting.

Condoleezza Rice, the US Secretary of State, will arrive in the region on Sunday, travel on to the Far East and return the following weekend. Western officials see that as Washington’s unspoken deadline for Israel to complete its operation.

The international outcry is growing louder. Kofi Annan, the UN Secretary-General, condemned Hezbollah for triggering the crisis but also denounced the Israeli response for its “excessive use of force”.

Jan Egeland, the UN’s emergency relief co-ordinator, predicted a humanitarian catastrophe if aid agencies were not allowed in, and said that about a third of the dead or wounded were children.

Fouad Siniora, the Lebanese Prime Minister, said that his country had been torn to shreds. He added: “Can the international community stand by while such callous retribution by the state of Israel is inflicted on us?”

Mr Annan gave the UN Security Council a six-point peace plan to be implemented as soon as hostilities cease. It calls for a beefed-up international force to help a strengthened Lebanese army to take over the south of the country from Hezbollah. It envisages the surrender of captured Israeli soldiers by Hezbollah to the Lebanese Government under Red Cross supervision, formal Lebanese recognition of the “blue line” border with Israel, a pledge of aid and an international mechanism to oversee the agreement. An international conference would set deadlines for disarming Hezbollah.

In Beirut yesterday thousands of foreigners clambered aboard a flotilla of vessels bound for Cyprus. Others remained trapped in southern Lebanon. “We are very, very scared,” said Hassan Fawaz, a UN translator who has spent eight days with 25 others in a basement in the village of Tibnine. “We are praying all the time. Pray for us too.”

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