A Syrian weapons facility was struck overnight by Israeli warplanes, a U.S. official told Fox News.  It is unclear what kind of planes. 

A source told Fox News that it is not clear whether the warplanes crossed into Syrian airspace or whether the missiles were fired from across the border. 

U.S. forces were not involved.

When Israeli planes fired on a weapons convoy inside Syria in January, they remained outside Syrian airspace. The convoy was believed to be carrying Russian SA-17 anti-aircraft missiles.

“Israel is determined to prevent the transfer of chemical weapons or other game-changing weaponry by the Syrian regime to terrorists, specially to Hizbullah in Lebanon,” an official from the Israeli Embassy in Washington told Fox News.

Pentagon spokesman George Little declined to comment on the report.

Fox News’ Jennifer Griffin and James Rosen contributed to this report.