Government forces and allied fighters are rapidly approaching the city of Deir Ezzor in eastern Syria, aiming to oust the Islamic State jihadist group and break a years-long siege.

- City under siege and divided -

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

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

But in 2014, as the Islamic State group rampaged across swathes of Syria and Iraq, it seized the territory held by opposition and rival jihadist forces in the province and gradually encircled the city.

By January 2015, the jihadist group held parts of the city and had besieged government forces and civilians in the rest of it, along with a key military airport and base on its outskirts.

Syria forces have managed to cling on to parts of the city despite regular IS attack.

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

Their advance cut the government-held parts of the city in two, with a southern section by the military airport now cut off from a northern sector.

Government forces hold the military airport and several adjacent southern neighbourhoods, along with part of the north of the city and the Brigade 137 base just outside it.

But areas are all circled by IS-held territory, with the jihadist group holding around half of the city, including several central neighbourhoods, according to the Britain-based Syrian Observatory for Human Rights monitor.

- Humanitarian concerns -

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

The United Nations said earlier this year over 90,000 people remained in areas under government control.

The Observatory puts the figure at around 150,000 and says over 10,000 people remain in IS-held parts of the city.

Experts say around 7,000 Syrian soldiers are also trapped inside.

The siege has created dire humanitarian conditions, with shortages of food, soaring prices and limited access to medicine and health care.

Syria's government has brought in supplies via military aircraft, but the process has been hampered by security concerns and damage to the military airport by IS fire.

The UN began air dropping aid into the city in April 2016, and it has staged dozens of deliveries of food and other humanitarian supplies.

But that route has also been fraught with difficulties, and the programme was briefly suspended after the IS advance in January during which the jihadists overran the aid dropzone.

Activists also report dire conditions in IS-held territory, particularly as Syria's army has neared, cutting supply routes.

Food and medical supplies have dwindled, and residents face water shortages and power cuts, one activist told AFP.

- Military advances on Deir Ezzor -

Syria's government has long sought to recapture Deir Ezzor and break the siege.

Restoring control of the broader province would also provide access to key oilfields and end the regime's dependence on imports.

After a string of victories achieved with Russian support and the implementation of several local ceasefires, the army has turned its attention to reaching Deir Ezzor.

Its offensive has unfolded on several fronts, including an approach from the west through the southern part of neighbouring Raqa province and another from central Homs province.

The campaign has seen the army recapture large stretches of territory in the Badia region, a desert area that spans several provinces, as well as key towns like Sukhna in Homs.

The army and allied fighters are now approaching Deir Ezzor city on four fronts, according to the Observatory.

At their nearest point they are just a handful of kilometres (miles) from Deir Ezzor city's western edge, battling to reach besieged forces inside the Brigade 137 base.

The advance comes amid speculation about a potential Deir Ezzor operation by US-backed forces that could seek to secure parts of the province to the east of the city

source:AFP