Largest town in region reported to be cut off as government forces press their advantage

Syrian government forces have surrounded the largest town in the besieged enclave of eastern Ghouta, in a prelude to a possible ground assault that could further inflame a dire humanitarian crisis.

Forces loyal to Bashar al-Assad have essentially split off Douma from the rest of eastern Ghouta, according to the Syrian Observatory for Human Rights, a day after a Red Cross and UN aid convoy arrived in the town to unload food supplies to thousands of civilians in desperate need. Douma was once one of the largest cities in Syria.

The report from the UK-based human rights group, which said both Douma and the smaller nearby town of Harasta were surrounded and cut off, was disputed by locals, but such an outcome seems inevitable in any event as the regime presses its advantage, backed by both Syrian and Russian airstrikes.

It also raises greater humanitarian concerns and fears for the lives of civilians living in the area, who have fled the government’s advance.

More than 1,000 people have been killed in the last two weeks of violence in eastern Ghouta, which borders the capital Damascus, according to Médecins sans Frontières, which has gathered data from hospitals in the area that it supports.

Q&A How bad is the situation in eastern Ghouta and is aid getting in? Show Hide In an attempt to convey the desperate and unyielding misery, the United Nations Children’s Fund released a blank statement on 20 February. A footnote said the agency has no words to describe the “children’s suffering and our outrage”. The UN secretary general, António Guterres, did have words: “Hell on earth." An estimated 400,000 civilians, already starved from years of blockade, are trapped amid relentless air strikes. ​Hundreds of people have been killed in the barrage that started on 18 February. Humanitarian groups are pleading for an urgent ceasefire to allow them inside. Aid workers say Syrian helicopters have been dropping barrel bombs - metal drums packed with explosives and shrapnel - on marketplaces and medical centres. Photograph: Mohammed Badra/EPA

Local doctors said that between 49 and 65 people had died on Friday, and the near-ceaseless shelling that started on 19 February resumed on Saturday morning. Accurate figures for the dead are impossible to collate because many bodies remain trapped under the rubble of destroyed homes, and others are buried without being taken to hospitals.

The violence has continued despite a UN security council resolution demanding a 30-day ceasefire and the delivery of humanitarian aid “without delay”. Residents have spent weeks living underground in bomb shelters, suffering food shortages and a lack of medical supplies, with doctors saying they are overwhelmed by the number of wounded.

Reports of chemical attacks that may have involved chlorine or organophosphorus have also emerged in recent days, despite warnings by western powers that use of chemical weapons might prompt them to intervene in the unfolding crisis.

The UN secretary general has described the situation in eastern Ghouta as “hell on earth” and the body’s high commissioner for human rights described the military offensive as a “monstrous annihilation”.

Facebook Twitter Pinterest Children collecting wood in the besieged town. Photograph: Bassam Khabieh/Reuters

The bombardment and encirclement of Douma continued even as rebels in the enclave, which is home to at least 300,000 people, acceded to a key demand by Russia: the evacuation of a few hundred al-Qaida-linked fighters in the enclave.

In a statement on Twitter on Friday, Jaish al-Islam, one of the main factions in eastern Ghouta, said the decision had been taken in consultation with the UN, a number of international parties and civil society representatives from eastern Ghouta. A few fighters were evacuated in an initial batch.

Jaish al-Islam and Faylaq al-Rahman, two Islamist rebel groups, control most of the opposition-held areas of eastern Ghouta. Any solution to the crisis will probably involve a partial evacuation of rebel fighters and perhaps civilians, in a deal similar to past surrender agreements between the government and rebels.

Moscow had justified the continued bombardment of the area by saying extremists remained embedded in the towns and were preventing civilians from taking advantage of a designated evacuation corridor to flee the fighting.

Q&A Which outside powers are involved in the Syrian war? Show Hide Over seven years, the civil war has dragged in multiple foreign nations, turning what started as a pro-democracy uprising into a quagmire of overlapping conflicts.

Global powerhouses including Iran, Israel, Russia, Turkey, and the United States have all, to different extents, engaged their militaries in the conflict. At the same time, they have supported warring factions on the ground, including Iran-allied Hezbollah, Kurdish militia, and the US-backed Syrian Democratic Forces alliance. Islamic State and al-Qaida are also present. Photograph: Bulent Kilic/AFP

Residents say they fear government retribution if they were to try and flee the area, or the possibility of being redrafted into the Syrian military and sent to fight on the frontline.

“If I thought about leaving Ghouta I would worry about the regime because there are no guarantees: and, second, I would worry about Jaish al-Islam, because they won’t let us leave,” said one activist in Douma. “If 100 families leave Ghouta, the regime will say they’ve evacuated all the civilians and then burn it all.

“We have no guarantees that the regime will protect the families that want to leave and that it won’t send the men to the frontlines,” he added.