Unconfirmed reports have claimed that the Israeli air force has attacked convoys near Syria's border with Lebanon.
The news reports follow several days of tension, during which there were suggestions of activity around installations where the regime of Syrian president Bashar al-Assad keeps a large stock of chemical warfare agents.
Israel's air force has been put on the highest state of alert, ready to react if the threat situation changes status, sources say. Israel has expressed concern that Assad's forces could lose control of their chemical weapons during a 24-month-old civil war.
Air force commander Maj Gen Amir Eshel recently expressed a deep concern about Syria's stockpile of chemical materials, and said all preparations were being made to deal with any potential threat.