IS' Shrinking Foothold in Syria's Deir Ezzor Province

Syrian government forces have expelled the last Islamic State group jihadists from the eastern city of Deir Ezzor in a two-month-long campaign backed by Russian air power, they announced Friday.

The city's fall reduces IS-held territories in the surrounding oil-rich province to just a few pockets.

It is another key defeat for the jihadists, who in recent months have lost most of the territory they seized in a lightning 2014 advance across Syria and Iraq.

- Besieged and divided -

Deir Ezzor city is the capital of the oil-rich province of the same name, which borders Iraq.

After Syria's uprising broke out in 2011 with anti-government protests, rebel groups and jihadists seized parts of Deir Ezzor and the surrounding province.

But in 2014, as the IS rampaged across Syria and Iraq, it seized the territory held by rival jihadist and rebel forces in the province and closed in on Deir Ezzor city.

By January 2015, it had captured parts of the city and imposed a siege on government forces and civilians in the remaining districts.

Regime forces managed to cling on to their enclave despite regular IS attacks.

Along with ally Russia, the regime has regularly carried out air strikes on IS-held rural areas, but the jihadists were still able to seize more territory in January.

Their advance split government-held zones of Deir Ezzor city into two: a northern enclave and a southern area near a key military airport.

At one point, the jihadist group held around half of the city, including several central neighborhoods, according to the Britain-based Syrian Observatory for Human Rights monitor.

But the army and allied fighters broke the siege on the northern part of the city on September 5, entering via the Brigade 137 base on its western edge.

- Humanitarian concerns -

Estimates vary over the number of people living in Deir Ezzor city, but agree the population has shrunk dramatically from its pre-war figure of 300,000.

The United Nations said earlier this year, before the siege was broken, that more than 90,000 people remained in areas under government control.

The siege created food shortages, sent prices soaring and limited access to medicines and health care.

Syria's government brought in supplies via military aircraft, a process hampered by security concerns and damage to the airport by IS bombardment.

The U.N. began air-dropping aid into the city in April 2016, but the program was briefly suspended after the jihadists advanced in January, overrunning the drop zone.

Activists reported dire humanitarian conditions in IS-held territory, particularly as Syria's army approached, cutting supply routes.

- IS faces multiple attacks-

On October 28-29, with regime forces back in control of most of the city, heavy clashes claimed more than 70 lives as government forces captured two new districts and the municipal stadium, the Observatory said.

The advance left IS encircled between the city and the Euphrates River, it added.

The group has already been expelled from neighboring Raqa province, and is now confined to just a few enclaves of Deir Ezzor province.

Syrian forces are now about 40 kilometers (25 miles) from its last remaining major position, the town of Albu Kamal on the Iraqi border. 

The group also holds a string of smaller towns and villages and at least one oil field, according to the Observatory.

Deir Ezzor province is rich with oil and gas fields that served as a key revenue stream for IS at the height of its power in 2014.

The regime offensive against it has been waged largely on the western side of the Euphrates, which cuts diagonally across Deir Ezzor province.

The Syrian Democratic Forces (SDF), Kurdish-Arab alliance backed by a U.S.-led coalition, is waging a second, separate offensive against the jihadists in the province's east.

The SDF on October 22 announced the recapture of Al-Omar, one of Syria's largest oilfields, a week after regime forces had seized the nearby town of Mayadeen from IS.

On Friday, state media said Syria's army and allied fighters had captured the last parts of Deir Ezzor city held by the jihadists, with Russian air support.

The Observatory said the advance leaves IS in control of around 37 percent of Deir Ezzor province, with the regime holding 32 percent.

The remaining territory is held by the SDF, the monitor said.