The latest air strikes killed at least five people and wounded nearly 20. News agencies estimate that at least 800 people have been killed in the 24 day conflict.
At the start of Friday, Israeli warplanes struck targets in Ouzai, a heavily Shia suburb of south Beirut, killing one Lebanese soldier and wounding three others.
The new strikes ended a week's respite for Beirut's southern suburbs which had been hit hard by Israeli aircraft in the earlier stages of the conflict between Israel and the armed Shia group, Hezbollah.
On Thursday Hezbollah's leader Hassan Nasrallah had threatened to launch rockets at Tel Aviv if Israel bombed Beirut.
Following the bombing of Beirut on Friday morning, civil defence officials in Tel Aviv published lists of bomb shelters in the city.
Seven Hezbollah rockets had landed in northern Israel by midday Friday. No casualties were reported.
Also on Friday, Israeli warplanes struck four bridges along Lebanon's coastal highway that connects the capital with the north of the country.
Police said the jets had destroyed the main bridge near the "Casino du Liban," in the Christian port of Juniyeh, as well as two others along the same road.
At least five people were killed in the strikes and more than 10 injured, the Red Cross said.
The bridges were practically the only useable road leading out of the country after Israel's bombardment of roads to other border crossing points in the east of the country.
The destruction of the bridges will make the distribution of food and medical supplies much harder, aid agencies warned.
"It's really a major setback because we used this highway to move staff and supplies into the country," said Astrid van Genderen Stort of the UN refugee agency UNHCR. "If we don't have new material coming in, we will basically be paralysed."
The largely Christian region north of Beirut had been largely spared by the Israelis who have been hitting Lebanon's infrastructure since July 12.
Lebanese security officials said that the Israeli the jets also hit a civilian car and a van on the coastal road in Juniyeh, wounding at least two people.
Israeli jets launched other attacks near Baalbek in eastern Lebanon and the Lebanese-Syrian border crossing at Masnaa, east of Beirut, Lebanese media said.
The Israeli military confirmed air strikes on Hezbollah targets across Lebanon, but did not give specific locations.
Arab television networks also reported on Friday that five Israeli soldiers had been killed in southern Lebanon. Hezbollah claimed to have destroyed an Israeli tank in the village of Aita al-Shaab.
Three of the Israeli soldiers were killed in a missile attack, said Al-Arabiya television. Israeli has not commented on the reports.
Israel says it had so far taken control of a zone containing 20 villages 6 to 7 km (3.7 to 4.3 miles) from the border.
The army says it has a plan to clear a 15 km (9 mile) security area in southern Lebanon, if authorised.
Israel now has some 10,000 soldiers in southern Lebanon.