Located about 90 miles (144.8 kilometers) from Raqqa, Daesh's previous self-proclaimed capital, Deir ez-Zor is now considered the "new headquarters" of the terrorist group, according to media reports. A government-controlled enclave remains in the city, which is partly-held by Daesh and surrounded by Daesh-controlled territory.
In April 2014, Daesh militants blocked the road linking Damascus, Palmyra and Deir ez-Zor, making the delivery of humanitarian aid impossible. The government-held part of Deir ez-Zor has been in a state of siege since September 2014. The army and civilians are provided with emergency supplies by air. Since the end of 2015, the Russian military has provided humanitarian assistance to the besieged city.
Since mid-January 2017, the number of militant attacks on residential areas and the military airbase has increased significantly. The government forces repeatedly repel attacks by militants attempting to seize the Deir ez-Zor Airbase. Aircraft based at the airbase provide fire support to Syrian troops fighting in and around the city.