Israeli forces attacked a convoy on the Syrian-Lebanese border on Wednesday, sources told Reuters, after Israelis warned their Lebanese enemy Hezbollah against using chaos in Syria to acquire anti-aircraft missiles or chemical weapons.

"The target was a truck loaded with weapons, heading from Syria to Lebanon," said one Western diplomat, adding that the consignment seemed unlikely to have included chemical weapons.

A source among rebels fighting Syrian President Bashar al-Assad said an air strike around dawn (0430 GMT) blasted a convoy on a mountain track about 5 kilometres (3 miles) south of where the main Damascus-Beirut highway crosses the border. Its load probably included high-tech anti-aircraft and anti-tank missiles.