The army and republican guard troops are breaking into the airbase area from the direction of the city's graveyard.
The offensive is being supported by aviation and artillery.
The operation to break the siege of Deir ez-Zor, which lies 140 km south east of Raqqa, began after four months of planning and preparation in the wake of the completion of the operation to liberate east Aleppo in January. This operation ended serious rebel activity in western Syria, allowing pro-government forces to turn their attention to the east across the country's desert region into Daesh heartlands.
On September 7, a source told Sputnik the US Air Force had evacuated Daesh field commanders from Deir ez-Zor. The US-led coalition denied the claims.
Russia has sent humanitarian aid to the city, but there has been none from the West.