US says the plane dropped bombs near coalition-backed forces, while Syria says its jet was flying in anti-ISIL mission.

A US fighter jet has shot down a Syrian government plane in Syria’s Raqqa province, officials from both sides have said.

The US-led coalition on Sunday said it downed the plane after it dropped bombs on American-backed forces fighting ISIL in northern Syria. Yet, the Syrian army said its jet was on a combat mission against the armed group’s fighters near the city of Raqqa, ISIL’s de facto capital in Syria.

The incident came as a monitoring group reported the first ground fighting between Syrian government troops and the US-backed alliance of Kurdish and Arab fighters.

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“At 6:43pm (17:43 GMT), a Syrian regime SU-22 dropped bombs near SDF (Syrian Democratic Forces) fighters south of Tabqa and, in accordance with rules of engagement and in collective self-defence of Coalition partnered forces, was immediately shot down by a US F/A-18E Super Hornet,” the Combined Joint Task Force said in a statement.

It said that two hours earlier, forces loyal to President Bashar al-Assad attacked SDF fighters in the town of Ja’Din south of Tabqa, “wounding a number of SDF fighters and driving the SDF from the town”.

Coalition aircraft then stopped the pro-government forces’ initial advance with a “show of force”, the coalition said, adding that it does “not seek to fight the Syrian regime, Russian or pro-regime forces” but would not “hesitate to defend” itself or its “partnered forces from any threat”.

Earlier on Sunday, the Syrian army said that “the so-called international alliance today noon targeted the jet over the area of al-Rasafa in the southern countryside of al-Raqqa while it was on a combat mission against the terrorist Daesh”, using an Arabic acronym of ISIL, which is also known as ISIS.

The pilot of the jet went missing after this “flagrant aggression”, the army’s command added in a statement, according to Syria’s state news agency SANA.

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The US-led coalition has in recent weeks escalated its aerial bombing campaign in northern Syria and Raqqa province. US-backed forces have encircled the city of Raqqa and captured several districts from ISIL fighters.

The Syrian army has also taken territory from retreating ISIL fighters in the western Raqqa countryside and seized back some oilfields and villages that had been under the group’s control for almost three years.

Following the downing of the Syrian plane, clashes between government troops and coalition-backed fighters broke out in two villages some 40km south of the city of Raqqa, the Syrian Observatory for Human Rights said.