UN Secretary General Ban Ki-moon on Thursday expressed "grave concern" over an alleged Israeli airstrike on sites in Syria, dpa reported.
"At this time, the UN does not have details of the reported incident," he said in a statement. "Nor is the UN in a position to independently verify what has occurred."
Ban called for "all concerned to prevent tensions or their escalation in the region, and to strictly abide by international law, in particular in respect of territorial integrity and sovereignty of all countries in the region."