Damascus: Syrian Republican Guard forces pushed into the rebel-held area of Douma in eastern Ghouta near Damascus on Friday, Syrian state TV reported, after a 10-day truce collapsed over disagreement regarding evacuation of opposition fighters.

The ground offensive began under the cover of air strikes, which left at least 36 people dead, including women and children, according to state media and opposition activists.

By sunset on Friday, artillery pieces, multiple rocket launchers and warplanes intensely pounded Douma. Live TV footage showed thick smoke billowing from different parts of the city as airstrikes create huge clouds of dust.

Douma is the largest city in eastern Ghouta. Government forces captured the entire region except for the city in a crushing offensive in February and March.

The city is a stronghold of the Jaish Al Islam, the rebel group holding out in Douma after insurgents in other parts of eastern Ghouta accepted safe passage out to opposition-held areas at the border with Turkey.

Violence resumed in and around Douma on Friday afternoon after Jaish Al Islam placed new conditions on the evacuation deal.

Before the fighting resumed, helicopters earlier on Friday dropped leaflets on Douma saying rebels should either leave to the northern town of Jarablus or hand over their weapons and receive amnesty with Russian and Syrian government guarantees that would include not drafting young men to the military service until after six to 10 months.

The leaflets also called on civilians to stay, saying their safety would be guaranteed by Russian Military Police deployed outside Douma.

Nearly 50 air strikes on Douma as of Friday afternoon killed at least 32 people, including children, according to the Britain-based Syrian Observatory for Human Rights. Douma-based activist Haitham Bakkar said at least 35 people were killed.

“We are being wiped out right now. We are being bombarded with barrel bombs and rocket launchers,” Bakkar said via text message from Douma. “The town is overcrowded and many people have no place to hide.”

Syrian state TV said several air strikes hit Douma after members of the Jaish Al Islam shelled government-held areas nearby killing and wounding a number of people.

State news agency SANA reported late on Friday that the shelling on government-held Damascus killed four and wounded 22 others.

UN spokesman Stephane Dujarric said the renewed outbreak of fighting in Douma “is of great concern to us”.

“There are still a number of people who are beseiged and trapped in the area,” he told reporters at the UN headquarters in New York, “We remind all parties that it is a violation of international law to target civilian infrastructure, to target civilians.”

The violence comes after nearly two weeks of calm in the last rebel-held town in the area after the Russians agreed with the Jaish Al Islam to evacuate the area toward rebel-held regions north of the country.

Earlier this week, hundreds of opposition fighters and their relatives left Douma toward northern areas controlled by Turkey-backed opposition fighters in the north. The evacuations were suspended on Thursday and state TV said Jaish Al Islam members have refused to release scores of government supporters they have been holding for years.

There have been reports that the group wants to negotiate a new deal, complaining of mistreatment by Turkish troops in northern Syria.

“There will be no further negotiations with terrorists over the evacuation deal. No one will be able to twist the army of the Syrian Arab Army,” said a state TV reporter as sporadic explosions could be heard in the background. “They will either release the detainees or the terrorists’ hideouts and offices will be destroyed.”

Jaish Al Islam official Ammar Al Hassan told The Associated Press that he has no information on whether the truce collapsed.

Earlier on Friday, a bomb exploded near a mosque in Damascus killing one person and wounding six others, according to state news agency SANA. It added that the blast occurred in the northeastern neighbourhood of Barzeh close to Al Khansaa mosque.

Such explosions have been rare in Damascus recently.

Barzeh is close to the eastern Damascus suburb of Harasta that opposition fighters evacuated last month following weeks of a crushing government offensive on eastern Ghouta.