The US-led coalition on Friday pulled aircraft from the skies above a convoy of Islamic State buses stranded in the Syrian desert so regime and Russian forces could go past, officials said.

Coalition drones had been circling the stranded 11-vehicle convoy for days and periodically picking off IS fighters if they strayed too far from the vehicles.

The buses themselves, which are packed with civilians believed to be family members, have not been targeted. As many as 200 jihadists and 200 civilians, thought to be family members, are on board.

The fighters had been headed from Lebanon to the Iraq border under an evacuation deal negotiated between IS and the powerful Lebanese Shiite movement Hezbollah, which has intervened in the war in neighboring Syria to prop up the Damascus government.

Russia notified the coalition through a special "deconfliction" line that regime forces were going to be passing through the area on their way to the city of Deir Ezzor, and asked for US aircraft to clear the area.

"To ensure safe deconfliction of efforts to defeat ISIS, coalition surveillance aircraft departed the adjacent airspace at the request of Russian officials during their assault on Deir Ezzor," the coalition said in a statement.

A US defense official told AFP the coalition was able to monitor the convoy until regime forces had passed through the area, but he would not say if the coalition was continuing to watch the buses.

The United States has repeatedly stressed that it was not party to the Hezbollah deal and said the fate of those aboard the buses was not a coalition issue.

"The regime's advance past the convoy underlines continued Syrian responsibility for the buses and terrorists," Brigadier General Jon Braga, director of operations for the coalition, said in a statement.

"As always, we will do our utmost to ensure that the ISIS terrorists do not move toward the border of our Iraqi partners."

source :AFP