The Israeli military says warplanes have dropped bombs on a bunker in southern Beirut where senior Hezbollah leaders were thought to be holed up.
Military officials say a wave of aircraft dropped 23 tons of explosives on the site late Wednesday.
Hezbollah said none of its leaders died in the Israeli airstrike. The guerrilla group said the bombs hit a mosque that was under construction, not a Hezbollah leadership bunker.
Southern Beirut is known as a Hezbollah stronghold.
Earlier Wednesday, Lebanon's Prime Minister Fouad Siniora made an emotional appeal for an end to the conflict pitting Israel against Hezbollah guerrillas.
In a televised address, Mr. Siniora called for international humanitarian aid for Lebanon, which has been battered in the conflict. He said Israeli attacks on Lebanon have killed more than 300 people and wounded one-thousand more.
Israeli air strikes on Lebanon Wednesday killed at least 61 civilians, the deadliest toll of the eight-day-old Israeli offensive. The Israeli military said two soldiers died in heavy clashes between Israeli troops and Hezbollah guerrillas in southern Lebanon.
The guerrilla group said one of its fighters died.
Hezbollah bombarded northern Israel with more rockets today, killing three people in the city of Nazareth, including two Israeli Arab children. Nazareth is home to a large Israeli Arab community.
Israeli Prime Minister Ehud Olmert has said Israeli attacks will continue until Hezbollah returns two captured Israeli soldiers and Israel is safe.
Thirty Israelis have died in fighting since Hezbollah guerrillas abducted the two soldiers during a cross-border raid on July 12th.