Civilians and fighters to be allowed out of east Aleppo in return for evacuation of people from rebel-besieged towns.

The evacuation of thousands of increasingly desperate Syrian civilians and fighters stranded in besieged east Aleppo is set to resume after a new deal was reached between rebel and the Syrian government.

Buses started entering several neighbourhoods on Sunday under the supervision of the Red Crescent and the International Committee of the Red Cross (ICRC), state news agency SANA said.

A source in Aleppo told Al Jazeera that as part of the latest deal, a total of 4,000 people will evacuate the Shia-majority towns of Fua and Kefraya in Idlib province, which are currently besieged by opposition fighters.

The source, who wanted to remain anonymous, said 1,500 people in the government-besieged towns of Madaya and Zabadani as well as everyone in eastern Aleppo will also be allowed to evacuate as part of this deal.

Syrian state media reported that government forces would only allow civilians and fighters to leave eastern Aleppo once families in Fua and Kefraya are evacuated.

Buses and Red Crescent vehicles arrived at the entrance to the two towns on Sunday, al-Manar TV, run by the Lebanese Hezbollah group, said on Sunday.

The new deal comes days after the Syrian government claimed victory in Aleppo, which had been partly under rebel control since 2012.

Busses and ambulances

Mohammed Shakiel Shabir, an aid worker based in rebel-held Idlib province, said approximately 100 buses were being prepared to collect the civilians from Khan al-Asl, a suburb of Aleppo city.

“We are taking several ambulances, food and medicines and approximately 100 coaches to Khan al-Asl,” he told Al Jazeera.

“Each coach can transport around 40 people so [God willing] we will be transferring thousands to safety.”

Reports differ on how many people remain in eastern Aleppo, with numbers ranging from 15,000 to 40,000 civilians, along with an estimated 6,000 fighters.

Emotional scenes unfold after #Aleppo residents reunite with families. Thousands are still trapped after evacuation plans came to a halt. pic.twitter.com/KWHETZSB45 — AJ+ (@ajplus) December 17, 2016

The evacuation of eastern Aleppo was suspended on Friday after rebels and government forces accused each other of violating an earlier deal.

According to the UN, more than four million people live in besieged or hard-to-reach areas in Syria, with limited or no access to food or medical supplies.

The UN Security Council is to expected to discuss the possible deployment of observers to Aleppo later on Sunday and vote on a resolution demanding immediate and unconditional access for UN staff to ensure the delivery of humanitarian aid.

According to several UN delegations on Twitter, the Council will meet for a special session at 12:00GMT to discuss a French-drafted resolution.

OPINION: I live in Aleppo, under siege

The draft resolution, obtained by the AP news agency, calls on Secretary-General Ban Ki-moon to immediately redeploy UN staff already on the ground to carry out “neutral monitoring” and “direct observation and to report on evacuations”.

It stresses that evacuations of civilians “must be voluntary and to destinations of their choice”.

Vitaly Churkin, Russia’s UN Ambassador, said on Friday he would examine the draft but was sceptical that monitors could be deployed quickly.

Aleppo, Syria’s second largest city and once a key cultural and economic hub, has been divided between government forces and rebels since 2012.

The evacuation agreements came a month after the Syrian government and allied militias launched a military offensive to retake the entire city. Syrian President Bashar al-Assad has hailed the operation as a victory.

The Syrian conflict started as a largely unarmed uprising against Assad’s rule in March 2011. It has since morphed into a full-scale civil war that has left hundreds of thousands dead and more than half of the country’s prewar population displaced inside and outside of Syria.