ANKARA, Turkey - In the first such incident since the U.S.-led coalition began airstrikes in September against Islamic State extremists in Syria, the Syrian government said Tuesday that its air-defense system had shot down a U.S. surveillance drone near the northern city of Latakia.

U.S. officials in Washington confirmed that controllers had lost contact with an unarmed drone in northwestern Syria but said they did not know what had happened to it. "At this time, we have no information to corroborate press reports that the aircraft was shot down," the Pentagon said in a statement attributed to a "defense official."

Turkish officials said the drone had been launched from the U.S. air base at Incirlik in southern Turkey and was one of four unarmed Predator drones based there.

The official Syrian news agency called the drone a "hostile U.S. surveillance plane," and the major question about the incident is whether its controllers had sent it intentionally over northwest Syria, an area far from Islamic State strongholds in eastern Syria, or if it had strayed off course.

Syria has allowed U.S., Jordanian and gulf state aircraft, including drones, to cross into its territory to bomb Islamic State targets since Sept. 23; until Tuesday, is not known to have used its advanced Russian-supplied air-defense system against them. Although the United States has said it has not cleared flights with Syria, Syrian President Bashar al-Assad recently told an interviewer that Iraqi officials have kept him briefed on bombing plans.

One Syrian who regularly sees Assad told McClatchy recently that Iraqi intelligence officials brief the Syrian government daily on plans for airstrikes. But the reported location of the downing, Latakia province, which abuts the Mediterranean, is far from the locations where the Islamic State is known to have been engaged in combat recently.