A Lebanese security source said on Wednesday that a reported attack by Israeli forces on a convoy near the Syrian-Lebanese border overnight had not occurred on Lebanese territory.

A western diplomat and regional security sources said earlier that Israeli forces had hit a convoy in the border area, a few days after Israeli Vice Premier Silvan Shalom said that any sign that Syria's grip on its chemical weapons was slipping could trigger Israeli intervention. There were no details of precisely where the action had occurred.

"There was no Israeli strike in Lebanon," the source told Reuters on condition of anonymity. "Not in the territory or near the border with Syria," he said, adding that he could not confirm or deny that there was a strike on Syrian territory.

President Bashar al-Assad has lost several military bases to rebels during a 22-month crisis. Israeli officials have been warning very publicly of a threat of high-tech anti-aircraft and anti-tank missiles reaching Israel's enemies in the Lebanese militant group Hezbollah, an ally of Assad, from Syria.