Israeli helicopters late on Thursday attacked Beirut airport, setting fuel tanks ablaze, in the second attack on Lebanon's only international air facility.
Israel first struck the capital's airport early in the morning and began enforcing a naval blockade, expanding reprisals since Hezbollah captured two Israeli soldiers a day earlier.
Police said 52 Lebanese civilians, including 15 children, were killed in attacks on Hezbollah targets in Beirut's southern suburbs and across southern Lebanon.
Security sources said the air strikes in south Lebanon also wounded 100 people. Ten members of a family were killed in Dweir village and seven family members died in Baflay.
Israeli warplanes later blasted runways at the main army air base in eastern Lebanon near Syria's border.
Lebanese police said that Israeli jets had dropped two bombs on the runway at the Rayak air base in the eastern Bekaa Valley, damaging it.
There were no reports of casualties.
Lebanon said on Thursday its only international airport will remain shut for at least 48 hours.
Mohammed Safadi, the transport minister, told reporters that "The airport will be partly operational within 48 hours, but reopening the airport is a political decision that will be decided by the cabinet,"
"The runways have all been hit, although some less than others," he said.
The air strikes triggered Hezbollah fighters to retaliate by firing rockets at northern Israel.
Israel media said at least 70 rockets had slammed into towns and villages in northern Israel.
Worst affected was the coastal city of Nahariya, nearly 10km south of the Lebanese border.
The Magen David Adom ambulance service said a 40-year-old woman was killed when a Katyusha rocket hit her apartment in Nahariya. Medics said 27 people, including children, had been wounded in the city.
Two Israelis were killed and many
wounded in Hezbollah attacks
They said seven rockets hit Safed, killing a man and wounding many.
Safed is some 15km inside the Israeli border with Lebanon and among the furthest struck.
Hezbollah said it had fired 60 rockets at Nahariya.
Hezbollah also said on Thursday that it would bombard Israel's third-largest city of Haifa if it targets Beirut. Haifa is 35km south of the Lebanon border.