Ceasefire reportedly holding in Syria’s Aleppo, but evacuation of civilians and rebels delayed for unknown reasons.

An agreed evacuation of rebels and civilians from the devastated Syrian city of Aleppo has been delayed, according to activists in besieged parts of the city and a monitor.

Busloads of people were due to begin leaving on Wednesday morning as part of a deal with the government, whose forces have effectively taken control of the entire city after weeks of heavy fighting.

No rebel or civilian had left eastern Aleppo as of 5am (03:00 GMT), according to the Syrian Observatory for Human Rights, a UK-based monitoring group that relies on a network of sources in the country to monitor the war.

"Save Aleppo. Save humanity." Residents of East Aleppo are giving their final messages to the world. pic.twitter.com/Hzd4VWp0wC — Al Jazeera English (@AJEnglish) December 13, 2016

The group did not give a reason for the delay of the evacuation. One Syrian rebel official told the Reuters news agency that pro-government Shia militias were obstructing the departure of people from opposition-held districts in a claim that could not be independently verified.

Zouhir Al Shimale, a journalist in east Aleppo, confirmed the delay, adding that the streets were mostly empty in the morning.

“People here are shocked [by the delay],” he told Al Jazeera. “We didn’t sleep last night waiting to leave.”

Explaining that civilians are fearful that the evacuation could be yet delayed further, Shimale said: “No one knows what the regime will do.”

Outside the scope of the evacuation agreement, the Russian government said at least 6,000 civilians were evacuated from eastern Aleppo and 366 rebels laid down their weapons and surrendured within the last 24 hours.

READ MORE: Message from Aleppo – ‘Tomorrow will be too late for us’

Russia’s UN ambassador announced late on Tuesday that all military action in east Aleppo had come to a halt and that the Syrian government was in control of the area.

“Over the last hour we have received information that the military activities in east Aleppo have stopped, it has stopped,” Vitaly Churkin told a heated emergency UN Security Council meeting.

“The Syrian government has established control over east Aleppo.”

Fears have been growing for thousands of trapped civilians as the opposition fighters make a desperate last stand in their remaining pocket of territory in their former stronghold.

“An agreement has been reached for the evacuation of the residents of Aleppo, civilians and fighters with their light weapons, from the besieged districts of east Aleppo,” Yasser al-Youssef, from the political office of the Nureddin al-Zinki rebel group, told AFP news agency.

He said the deal was “sponsored by Russia and Turkey” and would be implemented “within hours”.

Fears have been growing for thousands of trapped civilians in east Aleppo [AFP]

Huseyin Muftuoglu, a Turkish foreign ministry spokesperson, told Al Jazeera that civilians would first be evacuated from Aleppo, followed by rebels.

“They would move towards Idlib, according to the plan,” he said. “There is no plan to take them into Turkey.”

Later on Tuesday, Turkey’s Deputy Prime Minister Mehmet Simsek announced his government was planning to set up a new tent city to host “80,000 people fleeing eastern Aleppo”. He did not specify whether the “tent city” would be in Turkey or Syria.

#Turkey, the world's largest refugee hosting country, is to set up a tent city to accommodate up to 80,000 Syrian refugees fleeing #Aleppo. — Mehmet Simsek (@memetsimsek) December 13, 2016

News of the deal broke just minutes before the Security Council meeting on Aleppo began at UN headquarters in New York.

When asked by reporters shortly after the meeting if the fall of Aleppo was the end of the peace process, Staffan de Mistura, UN Syria envoy, said it “should be just the opposite”.

“We should be looking at this as a tragic opportunity to restart the political process.”

The UN earlier said that they received reports about pro-government forces executing scores of civilians in Aleppo, including women and children.

Eighty-two people were reportedly killed when Syrian forces took over rebel-held areas, it said.

Forces loyal to President Bashar al-Assad have in some cases entered homes and killed those inside, and in others “caught and killed on the spot” fleeing civilians, Rupert Colville, the UN rights office spokesman, said on Tuesday.

“The reports that civilians – including children – are being massacred in cold blood in their homes by Syrian government forces are deeply shocking but not unexpected given their conduct to date. Such extrajudicial executions would amount to war crimes,” Lynn Maalouf, Deputy Director for Research at Amnesty International’s Beirut regional office, said.

‘A surrender, not a ceasefire’

Haid Haid, a Syrian researcher and associate fellow at Chatham House, said the evacuation deal was more of “a surrender, not a ceasefire”.

“This situation will be similar to previous situations: rebels and civilians … would be allowed out, most likely to rural Aleppo or Idlib, and the Syrian regime will take over the rest of Aleppo,” he told Al Jazeera.

READ MORE: Civilians ‘killed on the spot’ as battle for Aleppo nears end

But with the Syrian government and its allies making steady progress on the battlefield, many were unsure that any deal would take place, Haid said.

“Negotiations have been ongoing for days now, and now the regime is sure that [it] is winning. So unless there is serious pressure from the international community on Russia on the regime, I think this deal might not even happen because they think they’re winning … why allow [the rebels] out if we can kill the rest of them there and now.”