UN chief Kofi Annan and UK PM Tony Blair have called for an international force to be sent to Lebanon.
Israel is continuing to bomb targets across Lebanon
The force could "stop the bombardment coming over into Israel and therefore gives Israel a reason to stop its attacks on Hezbollah", Mr Blair said.
The calls came as Israel struck targets across Lebanon for a sixth day, killing 15 people in air strikes in the north.
Two people were hurt in a new Hezbollah attack on the Israeli city of Haifa, where eight people died on Sunday.
Monday's rocket attack brought down a three-storey building in the city, Israel's third-largest, and rescuers were searching the rubble for more victims.
Lebanese guerrillas have been firing hundreds of missiles into Israel.
On Monday, Lebanese TV showed footage of what it said was an Israeli F-16 fighter aircraft falling from the sky over Beirut in flames. Israel said none of its aircraft had been shot down.
Mr Annan's call for an international force suggested a "package of actions, not exhortations" that would require parties to release prisoners, stop both rocket attacks into Israel and retaliatory action and "pursue this idea of a stabilisation force".
The call was made after talks between Mr Annan and Mr Blair on the sidelines of the G8 summit in the Russian city of St Petersburg.
It is unclear which countries would contribute to the force, and what its mandate would be.
A 2,000-strong UN mission has been monitoring the Lebanese-Israeli border since 1978 - but it does not have the power to enforce peace.
Israeli spokeswoman Miri Eisin told the BBC it was too early to consider the deployment of a new force.
However she added that her government would "welcome any international energised effort" to implement UN resolutions calling for the disarming of Hezbollah - which controls the Lebanese side of the border.
Israeli air raids
Israel launched its offensive last Wednesday following the capture of two of its soldiers by the Lebanese militant group Hezbollah. Since then, more than 130 Lebanese people have been killed.
Early on Monday, Israeli air strikes targeted the northern city of Tripoli, Lebanon's second-largest city, and the nearby port of Abdeh.
Fifteen people - including nine Lebanese soldiers - were killed in what Israeli said were attacks on radar stations used by Hezbollah there.
Two other people died when Israeli jets bombed northern parts of Beirut - including fuel tanks in the port area, where fires are raging. Targets in the Bekaa Valley in the East were also hit overnight.
Later, Israeli ground forces entered southern Lebanon. There are few details, but Israeli officials said this was not the start of an large-scale invasion.
They said that Israeli troops had crossed the Lebanese border back and forth in recent days.
In related developments:
- The evacuation of foreigners continues, as a cruise ship chartered by France was due to start picking nationals from EU countries
- EU foreign policy chief Javier Solana is due to brief EU foreign ministers in Brussels after his visit to Lebanon
- French Prime Minister Dominique de Villepin is due in Beirut as an expression of solidarity with the Lebanese people
- Iranian Foreign Minister Manouchehr Mottaki has gone to Damascus - a day after Tehran swore to stand by Syria if Israel attacked it.
Israeli forces have also kept up their offensive in the Gaza Strip - which began after an Israeli soldier was seized by Palestinian militants last month.
Two Palestinian militants were killed in separate air strikes overnight. The Palestinian foreign ministry building in Gaza City was hit for the second time in a week and largely destroyed.