A US-led coalition fighter jet has shot down a Syrian military plane in Raqqa province, the US has confirmed.
The SU-22 fighter-bomber was engaged by an F/A-18E Super Hornet after it had dropped bombs near the US-backed Syrian Democratic Forces, the Pentagon said.
It is the first time in the Syrian conflict that the US-led coalition has shot down a Syrian Jet.
Syria condemned what it called a "flagrant attack" that would have "dangerous repercussions".
In a separate incident, Iran's Revolutionary Guards said that they had launched several missiles from Iran into the eastern Syria on Sunday, targeting the ISIS fighters.
The SU-22 incident took place on Sunday afternoon near the town of Tabqa, where the Syrian Democratic Forces (SDF) have been fighting Islamic State militants as part of a drive to retake the city of Raqqa, the ISIS stronghold further to the east.
The Syrian army said its warplane was on a mission against IS when it came under fire, according to state television.
It said the incident would have "dangerous repercussions" on efforts to fight terrorism.
An army statement said the pilot of the plane was missing.
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.
Although this is the first time the coalition has shot down a Syrian jet, there have been an increasing number of incidents between the two sides.
CCTV footage of the ISIS Attack on the Tehran Parliament Building:
The Missiles were apparently in response to an ISIS-claimed attack on the Iranian parliament earlier this month which killed more than a dozen people.
"The spilling of any pure blood will not go unanswered," a Guards statement said.
Iran has been a key ally of the Syrian President Bashar Al Assad, sending
military advisers and thousands of "volunteer" troops.