Fighting has erupted in Lebanon between Hezbollah and Syrian rebels, leaving at least 15 people dead.
Lebanese media reported that Hezbollah fighters were preparing to launch rockets when they were attacked by the Syrian rebels.
Syrian opposition fighters have threatened to attack Hezbollah, after the Lebanese movement got involved in the Syrian conflict, taking the side of the embattled president Bashar al-Assad.
Meanwhile a UN Security Council move to issue a declaration voicing concern over the siege on Qusair was blocked by Russia.
Qusair is in rebel hands, but Syrian forces and Hezbollah fighters have surrounded the town and are attempting to regain control.
Russia said it blocked the declaration as there was no such move by the UN when the rebels captured Qusair last year.