Two roadside bombs exploded in southern Lebanon on Monday, killing a Hezbollah commander in an attack that guerrillas blamed on Israel.
Iranian-backed Hezbollah vowed to retaliate against the Israelis.
A statement issued in Beirut by Hezbollah identified the victim as Ali Hassan Deeb, better known as Abu Hassan.
The commander was instantly killed when two bombs on the side of the road exploded simultaneously next to his sedan in a suburb of Sidon, the provincial capital of southern Lebanon, Lebanese security officials said.
The explosions tossed the vehicle about 30 feet off the road and turned it into blackened wreckage. The bombs were apparently triggered by remote control.
Sources close to Hezbollah who spoke on condition of anonymity said Abu Hassan, 42, was the "coordinator of operations" for Hezbollah in southern Lebanon.
There was no immediate claim of responsibility for Monday's bombing in Sidon, a port city 25 miles south of Beirut.
But the guerrillas promised retaliation. Sheik Nabil Kaouk, the Hezbollah commander in southern Lebanon, blamed Israel and its prime minister, Ehud Barak, whom he described as the "No. 1 terrorist."
A spokesman for the Israel Defense Forces declined to comment on the attack.
Israeli television reported that Abu Hassan was at the top of Israel's most-wanted list for carrying out attacks against Israeli soldiers in an Israeli-controlled strip of southern Lebanon, where Hezbollah has been fighting the occupation forces since 1985.
The Hezbollah statement on the bombing said Abu Hassan was a "senior holy warrior" who survived several assassination attempts and lost a son, Hussein, in fighting against the Israeli occupation forces.
Abu Hassan is survived by his wife and five children.
Meanwhile, Hezbollah guerrillas attacked Israeli and allied outposts in the occupied zone late Monday, wounding an Israeli-allied militiaman, Lebanese security officials said.
Also late Monday, Israeli jet fighters and helicopters attacked positions believed held by Hezbollah to the north of the occupation zone, a security source said.