US-led coalition jets bombed a Syrian army position at Jebel Tharda near Deir al-Zor airport on Saturday, killing dozens of Syrian soldiers, Russia and a war monitoring group said, paving the way for Islamic State fighters to overun it. Syria's army general command said in a statement that the air strike was "conclusive evidence" of US support for Islamic State, noting that the strike was "dangerous and blatant aggression".
Islamic State said in a statement on its Amaq news channel that it had gained "complete control" over Jebel Tharda. The defence ministry in Russia, which has been aiding Syria's President Bashar al-Assad in the five-year-old civil war, said US jets had killed more than 60 Syrian soldiers in four air strikes and that a fierce battle was now taking place near the airport.
The Syrian Observatory for Human Rights, a Britain-based monitoring group with contacts across the country, cited a military source at Deir al-Zor airport as saying that at least 80 Syrian soldiers had been killed in the strike. Russia's Defence Ministry said that if the coalition bombing was a mistake, it was evidence of Washington's "stubborn refusal" to co-ordinate its actions with Russia's government. The US-led coalition has been conducting air strikes against Islamic State since September 2014 and is also supporting rebels against Assad elsewhere in Syria. In December, Damascus accused US coalition warplanes of striking an army camp near Deir al-Zor, but Washington said it was done by Russian jets.