In the latest events, Lebanese police announced that Israeli warplanes had struck a bridge Friday on the coast road 20 kilometres north of Beirut near the Christian port of Juniyeh.
A Lebanese Red Cross official later said at least two civilians were killed and 12 wounded when Israeli warplanes struck four bridges along the coastal highway leading north from Beirut towards the Syrian border.
The region targeted had up to now been largely spared by the Israelis who have been hitting Lebanon's infrastructure since July 12.
Five Israeli soldiers killed
Reuters later said Hezbollah guerrillas killed five Israeli soldiers in ferocious fighting in south Lebanon.
Quoting Lebanese security sources, Reuters said Hezbollah guerrillas detonated roadside bombs and fired anti-tank rockets and assault rifles at Israeli forces occupying seven small enclaves.
The guerrillas also battled forces trying to launch new incursions near the village of Markaba and a strategic hill near the coastal town of Naquora.
Israeli aircraft launched more than 100 strikes on targets across the south while artillery pounded areas close to the border with hundreds of shells.
Hezbollah said in a statement its guerrillas destroyed a tank and battled infantry units near Markaba, just inside Lebanon, from midnight, inflicting several Israeli casualties.
In another statement, the group said there was house-to-house fighting in the village of Aita al-Shaab overnight.
Five Israeli soldiers were killed in fighting with Hezbollah guerrillas near the southern village of Markaba today, Al Arabiya television said.
The satellite station, which earlier said three soldiers were killed, gave no further details.
In Tel Aviv, a military spokesman refused to comment on the report.
Eight Israelis killed
Earlier, eight Israeli civilians were killed in another barrage of Hezbollah rockets while at least three soldiers died in fire fights with the militia.
As Israel stepped up its ground offensive more than 100 rockets hammered northern Israel.
"Overall in terms of casualties, this is the hardest day," an army spokeswoman said.
Israeli warplanes had earlier thundered over Beirut ending a six-day lull in an onslaught that Lebanese officials say has killed more than 900 people in the 23-day conflict.
Pamphlets later landed on the south of the capital warning that bombing of the area would be extended and urging civilians to leave.
Israeli aircraft later bombed southern Beirut, stronghold of the Shiite Muslim Hezbollah movement, for the second consecutive night
Hezbollah chief Hassan Nasrallah has threatened to strike at Israel's commercial capital of Tel Aviv if central Beirut is hit by air strikes.
"If you bombard our capital we will bombard the capital of your aggressive entity," he said in a televised speech.
Israeli public television quoted a senior military official as saying that its army would destroy all Lebanese infrastructure if Hezbollah carried out its threat.
The country's parliamentary majority leader, Saad Hariri, later said that Lebanon hoped a ceasefire in the current conflict would be achieved next week.
"We hope that a ceasefire will be achieved next week," Hariri was quoted by ITAR-TASS news agency as saying.
Olmert to pursue objectives
Premier Ehud Olmert said his country would pursue its drive against
Hezbollah guerrillas in south Lebanon until an international force of about 15,000 combat-ready troops was deployed there.
"There should be overlap in terms of time so that we will pull out and they will come in without a time gap that will allow Hezbollah to rebuild their position in the south of Lebanon," he told The Times of London.
An army spokeswoman said Israeli ground troops were operating around 20 border villages in south Lebanon today in a bid to push Hezbollah fighters further north.
They were conducting operations "inside and outside" the villages of Marun al-Ras, Taibe and Markaba, among others, she said.
Israeli Defence Minister Amir Peretz ordered the army to prepare for the possible push north to the Litani river, 20km north of the border.
Launching a ground offensive as far as the Litani would need the approval of Prime Minister Ehud Olmert's cabinet, since it would mean sending forces well beyond a planned "security zone".
"No decision has been made," said Brigadier-General Ido Nehushtan.
But, he added, the army "is ready and prepared to take what action is required."
An invasion up to the Litani would be Israel's deepest push into Lebanon since 1982.
Reuters quoted political sources as saying Mr Olmert has so far objected to sending soldiers as far the Litani and is not convinced it would halt Hezbollah rocket fire into Israel.
Israel said it had so far carved out a zone containing 20 villages 6 to 7km from the border.
Major Zvika Golan, spokesman for the Israeli northern command, said the army had a plan to clear a 15km security area in southern Lebanon, if authorised.
Meanwhile Lebanese Prime Minister Fouad Siniora told the BBC his country would run out of fuel in about a week if it did not get new supplies.
A Lebanese soldier was killed on Friday when Israeli jets bombed a military position in Ouzai in the south of Beirut in an early morning raid, an army officer said.
Earlier, a young woman was killed and three other civilians were wounded in an Israeli air strike near the eastern Lebanese town of Baalbek, a day after a commando raid captured five alleged Hezbollah militants.
Israeli casualties
Overnight, seven civilians, including an 80-year-old couple, were killed in an intense bombardment of the Tyre region in south Lebanon.
Three Israeli soldiers were killed and four others were wounded during clashes with Hezbollah guerrillas in the flashpoint village of Aita ash-Shaab in southern Lebanon, the army said.
Al-Arabiya news channel said a fourth soldier was killed and another wounded in fire-fights in Adayssa in south Lebanon but Israel declined to comment on the report.
A total of 40 Israeli soldiers have been confirmed killed since the start of the offensive. Israel claims to have killed hundreds of Hezbollah fighters but the militia says its losses are much lower.
It said four of its fighters were killed Thursday, bringing the number of guerrillas killed since the start of the offensive to 48.
The fresh strikes came after Hezbollah fired an unprecedented salvo of rockets at Israel, in apparent retaliation for an Israeli commando operation in which five suspected guerrillas were snatched from a hospital.
Hezbollah has since fired another barrage rockets into Israel killing at least eight Israeli civilians. Police reported that more than 100 rockets had slammed into the north region.
Syrian-made missile
In Tehran, one of the Iranian founders of Hezbollah, Ali Akbar Mohtashami-Pour, said the militia had missiles which leave "no spot in Israel unreachable."
The repeated barrages came as a blow to Israeli claims to have crippled Hezbollah's ability to launch rockets, Israel's main stated objective of its war in southern Lebanon.
A military source said that, for the first time, Hezbollah fired a Syrian-made Fajer-5 missile, with a longer range and larger warhead, hitting the northern town of Rosh Pina but causing no casualties.
The militia has fired more than 2,000 rockets at northern Israel since the start of the offensive, killing 25 civilians.
Israel had called a 48-hour partial halt to air attacks after it raided the Lebanese village of Qana Sunday. Reports that 52 civilians had been killed, mostly women and children, fuelled worldwide calls for an immediate ceasefire.
On Thursday Lebanese officials reduced the Qana toll to 28 dead, including 16 children.
An Israeli army probe said the military did not know there were civilians in the building and would not have attacked if they had.
Gaza attacks
Palestinian hospital sources said two Palestinians were killed and a third was wounded Friday when an Israeli tank fired a shell during a major incursion in Rafah in the south of the Gaza Strip.
In the same area four Palestinians, including two armed militants, were wounded in an Israeli air raid, the sources said.
Israeli aircraft also carried out a night raid against a house in Gaza belonging to a member of Hamas, wounding three Palestinians, medical sources said.