The Pentagon said it had halted an airstrike over Syria after Russia and the Syrian Government accused US warplanes of responsibility for killing at least 62 Syrian soldiers.

In a statement, the US military's Central Command admitted it had been carrying out a strike against a suspected Isis (Islamic State) position in the eastern province of Deir al-Zour, but said it called off the assault after Russia said it was Syrian Army positions that were being attacked, and not Isis.

An Obama Administration official expressed US regret for "unintentional loss of life", AP reported.

The official says the United States has "relayed our regret" for the unintentional loss of life. The official says the notification was sent through Russia.


Earlier, Syria and Russia had accused the US-led coalition of striking a Syrian Army base and blamed the raid for an Isis advance in the area.

The developments come amid an already fragile ceasefire brokered by Russia and the United States.

The United States and its allies began launching strikes on Isis targets in Iraq and Syria in 2014. Russia has launched its own raids since intervening to prop up the Syrian government a year ago.

Russia's Defence Ministry said that more than 60 Syrian troops were killed in four airstrikes near the city of Deir al-Zour, the Interfax news agency reported.

DPA reported that the Syrian Observatory for Human Rights said that the airstrikes killed at least 83 Syrian soldiers and injured 120.

The troops were surrounded by Isis fighters, and the strikes "paved the way for Isis terrorists to attack" a nearby hilltop, Syria's military said in a statement reported by the state-run news agency.

The statement said the alleged strikes were "conclusive evidence that the United States and its allies support Isis and other terrorist organisations".

The Russian Defence Ministry accused the United States of refusing to coordinate its operations with Russia in Syria.

Earlier this month, the two world powers struck a ceasefire agreement, which took effect on Tuesday. The accord calls for a nationwide truce, but that excludes attacks on Isis and a former al-Qaeda affiliate, Jabhat Fatah al-Sham.

Under the agreement, aid agencies should have unrestricted access to besieged populations. But so far, the United Nations has struggled to bring assistance to civilians in blockaded areas.

Nearly half a million people have been killed in the Syrian conflict since 2011.