UNITED NATIONS - UN Secretary-general Ban Ki- moon on Sunday voiced his "grave concern" at reported Israeli airstrikes on Syria, calling on all sides to "exercise maximum calm and restraint."

"The secretary-general expresses grave concern over reports of airstrikes in Syria by the Israeli Air Force," said a statement issued here by Ban's spokesman.

"At this time, the United Nations does not have details of the reported incidents," the statement said. "Nor is the United Nations in a position to independently verify what has occurred."

Syria has deployed missile defense batteries toward Israel in response to the Israeli attack that targeted a Syrian army facility in the capital city of Damascus earlier on Sunday, media reports said.

Syria's state media accused Israel of trying to give a boost to the Syrian rebels after their recent frustrations. The Israeli government has so far made no official comments on the reported attack.

"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," the statement said.

"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," it added.