Security sources in Israel said the planes raided a "terrorist target" just outside Beirut, while a Lebanese military source gave no report of casualties.

The planes fired two missiles at disused positions of the Popular Front for the Liberation of Palestine-General Command (PFLP-GC) on the Mediterranean coast at Naameh, a PFLP-GC official told AFP.

"We don't know exactly what was targeted," he said.

The Israeli sources said the targeted site was used by the PFLP-GC, which is led by Ahmed Jibril. Israel's air force often targets the positions in Naameh which the PFLP-GC, based in Damascus, says it vacated several years ago.

The air strike was apparently in response to an earlier mortar attack which Israel said targeted one of its naval vessels patrolling in Israeli territorial waters.

Lebanese security sources said three rounds landed inside Lebanese territory and a fourth in the Mediterranean.

The Israeli military said the mortar rounds had been aimed at an Israeli naval ship in territorial waters, but the attack caused neither casualties nor damage.

"It was a provocation by the terrorist organisations which operate from Lebanon under the protection of Syria and put our citizens and forces in peril," said Captain Sharon Feingold.

"We continue to hold the Lebanese and Syrian governments responsible for these operations which take place under their protection."

The military did not confirm a report on Israeli public radio which said the rounds were fired by the Lebanese Shiite Muslim fundamentalist Hezbollah militia.

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