The US and five Arab allies have launched the first strikes against Islamic State (IS) militants in Syria.
Islamic State militants in Raqqa province said a US drone crashed during the air strikes against them
The Pentagon said warplanes, drones and Tomahawk missiles were used in the attacks, which targeted several areas including IS stronghold Raqqa.
Syria's foreign ministry said its UN envoy was informed about the strikes against IS, which controls large swathes of Syria and Iraq.
The US has already launched about 190 air strikes in Iraq since August.
However, Monday's action expands the campaign against the militant group across the border into Syria.
Pentagon spokesman Rear Adm John Kirby confirmed the operation, saying "US military and partner nation forces" had undertaken military action in Syria.
US Central Command (Centcom) said Sunni Arab countries Bahrain, Jordan, Qatar, Saudi Arabia and the United Arab Emirates "participated in or supported" the strikes.
The militants said the US drone came down after crashing into a communications tower in Raqqa
It said a total of 14 strikes destroyed or damaged IS training compounds, command and control facilities, vehicles and storage sites.
The US military will continue to conduct air strikes against IS targets in Iraq and Syria, it added.
Separately, Centcom said US forces also attacked a network of al-Qaeda veterans named Khorasan who had established a safe haven west of Aleppo and were plotting imminent attacks against the West.
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