Syrian rebel forces began withdrawing from an enclave northeast of Damascus on Saturday and will move into the northern part of the country, after government troops launched air strikes and artillery attacks. The militants began evacuating the al-Rheibeh, Jairoud and al-Nasseriyeh areas in Qalamoun enclave outside Damascus after a deal with government troops, Syrian state television reported.

The Syrian Arab News Agency said that 27 buses entered al-Rheibeh city on Saturday morning to “transport terrorists and their families from the three towns to Jarablos and Idleb”.

Said Seif, a spokesperson for the Ahmad Abdo Martyr brigade, a rebel group in Qualamoun told Reuters that the militants agreed to the deal after intensified Russian shelling killed six people. “This made the Free Syrian Army factions sit at the negotiating table with the Russian side and an agreement was reached the most important articles of which are the surrender of heavy weapons and the departure of fighters to the north,” he said.

The agency said Syrian state TV showed clouds of smoke rising from the al-Hajar al-Aswad district, which is part of an enclave including the Palestinian Yarmouk camp. The Islamic State group has been in control of the camp since 2015. An unidentified commander who fights for the Syrian government claimed army helicopters targeted Islamic State positions.

A United Nations Relief and Works Agency spokesperson said the organisation was “deeply concerned” about the fate of civilians, including 12,000 Palestinian refugees in Yarmouk and the surrounding areas. “Displacement continues with people moving to the neighboring area of Yalda, to escape the fighting,” Chris Gunness said. He added that some families were unable to move due to the intensity of fighting.