Ban Ki-moon
Ban Ki-moonOfficial Photo/UN

UN Secretary General Ban Ki-moon appealed Sunday for restraint to avoid an escalation in the Syrian conflict, expressing "grave concern" over Israeli air strikes, AFP reported.

"The secretary-general calls on all sides to exercise maximum calm and restraint, and to act with a sense of responsibility to prevent an escalation of what is already a devastating and highly dangerous conflict," his spokesman Martin Nesirky said.

Nesirky said the United Nations was unable to independently verify the Israeli strikes, and had no details about them, but Ban "expresses grave concern over reports of air strikes in Syria by the Israeli Air Force."

"The secretary-general urges respect for national sovereignty and territorial integrity of all countries in the region, and adherence to all relevant Security Council resolutions," Nesirky said.

Israel launched an air strike near Damascus on Sunday, the second in a 48-hour period targeting the transfer of arms to Lebanon-based Hizbullah, a senior official told AFP on condition of anonymity.