According to an eyewitness in the Bekaa Valley, Hezbollah militants were seen taking their positions in the mountainous Knessineh area overlooking the Israeli-Lebanese border shortly after the Golan incident took place.

However, no one was hurt and it was not immediately clear who was responsible, an Israeli military spokesman said.

Lebanese security sources said that all precautionary measures have been taken by the Lebanese Army and UN peacekeepers in southern Lebanon to prevent any incident that would breach the ceasefire between Lebanon and Israel.

Hezbollah and Israel fought 33 days of fierce battles in 2006, after the Shiite group snatched two Israeli soldiers in a cross-border attack.

The fighting came to an end after the UN Security Council issued Resolution 1701 calling for a halt to all violence in August 2006 and called on the Lebanese Army and UN forces to monitor the situation on the border.

Intensifying patrols

It was believed that the firing of shots in the Golan Heights was by Palestinian militants in protest at Israel's offensive in the Gaza Strip and cause tension on a second front.

Meanwhile, the Lebanese Army and UN peacekeepers intensified their patrols on the Lebanese side of the border to prevent any incident similar to Thursday's firing of Katyusha rockets into northern Israel.

Hezbollah has denied it fired the salvo into northern Israel, and officials in both Israel and Lebanon said it was probably the work of a radical Palestinian faction.

Day 16 of Gaza campaign

Israeli forces moved into the Gaza Strip's most populous area on Sunday, killing at least 29 Palestinians on the 16th day of their ground offensive. Israeli Prime Minister Ehud Olmert said his country was close to achieving its aims.

"Israel is getting close to achieving the goals it set for itself," Olmert told his cabinet in Jerusalem, giving no timeframe for an end to a campaign launched with the declared aim of ending Hamas rocket attacks.

"But patience, determination and effort are still needed to realize these goals in a manner that will change the security situation in the south," Olmert said, referring to Israeli towns where life has been seriously disrupted by rocket salvoes from Hamas militants in Gaza.

Thick black smoke rose over the city of Gaza as fighting raged on in the Hamas-ruled territory in defiance of international calls for a ceasefire. Medics said about half the Palestinians killed on Sunday were civilians.