An American warplane has shot down a Syrian military aircraft that dropped bombs near US-led coalition fighters in western Raqqa, the US military says.
US Central Command issued a statement saying the plane was downed "in collective self-defence of coalition-partnered forces," identified as fighters of the Syrian Democratic Forces (SDF) near the city of Tabqah.
The Syrian army said earlier that the US-led coalition shot down one of its planes during a combat mission against Islamic State militants. Washington is leading an alliance in the fight against Islamic State in Syria.
"[The] flagrant attack was an attempt to undermine the efforts of the army as the only effective force capable with its allies ... in fighting terrorism across its territory," it said.
"This comes at a time when the Syrian army and its allies were making clear advances in fighting the Daesh [Islamic State] terrorist group."
An army statement released on Syrian state television said the plane crashed and the pilot was missing. It said the incident took place on Sunday afternoon (local time) near a village called Rasafah.
The US-led coalition, which has in recent weeks escalated its aerial bombing campaign in northern Syria and Raqqa province, has encircled the city of Raqqa and captured several districts from the militants.
The Syrian army has also taken territory from retreating Islamic State militants in the western Raqqa countryside and seized back some oil fields and villages that had been under the militants' control for almost three years.