BEIRUT, Lebanon (AP) _ Guerrillas attacked a string of military posts in the Israeli-occupied zone of south Lebanon early today, provoking airstrikes and artillery shelling, Lebanese security officials said.

Hezbollah guerrillas claimed responsibility for the rocket and machine-gun attacks, which began shortly after midnight Tuesday, saying they scored ``direct and definite hits'' on several positions.

The security officials, speaking on condition they not be identified by name, confirmed the attacks, saying Israeli troops and their allied militiamen responded by shelling the source of fire north of the Israeli-occupied enclave.

An Israeli helicopter gunship fired two missiles at targets in a valley near the village of Majdel Silim.

There was no immediate report of casualties or damage, the officials said.

Israel had no immediate comment on the fighting.

On Tuesday, Israeli warplanes fired four missiles at suspected guerrilla hide-outs in Iqlim al-Tuffah, a Hezbollah stronghold facing the enclave, causing no casualties.

Israel plans to withdraw from the enclave by July 7. It set up the zone in 1985 as a buffer against cross-border guerrilla attacks on its northern communities.