The U.S. military has confirmed that it has lost contact with an unarmed Predator drone that had been flying over northwestern Syria and which forces loyal to dictator Bashar al-Assad claim to have shut down, the Los Angeles Times reported.

An unidentified official told the newspaper that U.S. forces lost contact with the drone about 1:40 p.m. on Tuesday. The reason for its disappearance is being investigated, the source added.

Predator drones have been flying daily missions above the large swaths of territory across Iraq and Syria that are under control of the ISIS terror organization. President Obama last summer authorized strikes against the group, which refers to itself as the "Islamic State."

The Syrian Arab News Agency (SANA), a mouthpiece for the Assad regime, said government forces had shot down the drone; if the report turns out to be correct, it will mark the first time an American aircraft has gone down since the United States and its allies began striking targets in the Arab country.

"Syrian air defenses brought down a hostile U.S. surveillance plane in northern Latakia," SANA said in a bulletin, without giving further details, Reuters noted.

Nevertheless, "at this time, we have no information to corroborate press reports that the aircraft was shot down," an unnamed U.S. defense official told the British news service, speaking on condition of anonymity. "We are looking into the incident and will provide more details when available," the source added.

Other unidentified U.S. officials told ABC News that it was unclear if drone was shot down or if it crashed due to mechanical problems.

While the Syrian military has one of the largest air defense systems in the Middle East, the forces loyal to Assad have not engaged U.S. or coalition aircraft overflying Syria in the past, presumably because they were targeting ISIS -- a common enemy.

If the drone was indeed brought down by Syrian air defenses, the dynamic for the American and coalition aircraft flying in Syrian airspace would change, the network judged, as they could no longer count on the "free rein" they have enjoyed up until now.