Civilians and rebel forces are yet to depart from the besieged city of Aleppo, after a planned evacuation Wednesday morning was delayed.

The first evacuees were expected to depart at 0300 UTC after rebel forces and the Syrian government reached a temporary truce agreement. However, some two hours later, no civilians have yet been able to leave.

The Syrian Observatory for Human Rights said it expects the evacuation to still go ahead, ascribing the delay to disagreements between Russia and the Syrian government.

Earlier, one Syrian rebel official told news agency Reuters that Iranian Shiite militias were obstructing the departure and turning people back. Military officials loyal to Assad could not be reached to comment.

More than 30 buses remain parked on the government-controlled side of the front line, waiting to ferry people out.

The withdrawal of rebel forces will hand control over the last rebel-held pockets of Aleppo to government forces, marking the biggest victory yet for Syrian President Bashar al-Assad and his coalition after more than five years of civil war.

Truce holding 

The temporary truce and evacuation agreement was the result of talks between Russia, Assad's main coalition ally, and Turkey, a leading backer of rebel forces.

Russia's UN envoy Vitaly Churkin told the United Nations Security Council late on Tuesday: "Over the last hour we have received information that the military activities in east Aleppo have stopped. The Syrian government has established control over east Aleppo."

As part of the effective surrender, rebel fighters and their families were to start withdrawing on Wednesday morning, as President Bashar al-Assad's troops continue to close in. The Syrian military did not mention civilian evacuations as part of the deal, however Turkey and several rebel groups said there was a deal to also let civilians evacuate .

"An agreement has been reached," Yasser al-Youssef of the Nurredin al-Zinki rebel group told French news agency AFP. "The first stage will be the evacuation of civilians and wounded, within hours, and afterwards fighters will leave with their light weapons."

Other rebel sources confirmed that the first buses were being prepared to take civilians and some fighters out of eastern Aleppo, and that the evacuation to safer parts of Syria was to begin shortly.

An official from one rebel group told news agency Reuters that as many as 50,000 civilians were waiting to leave.

Most are expected to travel to the rebel stronghold of Idlib province. However, in spite of Tuesday' truce deal, the Syrian civil war continues to rage on. The UN envoy for Syria, Staffan de Mistura, expressed concern following the deal that Idlib could become the next target for the Syrian military.

However, Churkin insisted that civilians were not required to leave the city after the government reasserted its power. "The civilians, they can stay, they can go to safer places, they can take advantage of the humanitarian arrangements, which are on the ground," he said.

'A complete meltdown of humanity'

The UN's human rights office said it received reports of pro-government forces killing at least 82 civilians, including 11 women and 13 children, in the last pockets of rebel-held territories in the embattled city.

The situation in Aleppo indicates "a complete meltdown of humanity," UN humanitarian spokesman Jens Laerke said on Tuesday.

Spokesman for the UN human rights' office Rupert Colville said his body has received reports of pro-government forces entering civilian homes and killing those individuals found inside."

The US Ambassador to the UN, Samantha Power, told the UN Security Council Tuesday that Syria and its allies, Russia and Iran, are responsible for the "the conquest of and carnage in Aleppo."

"Are you truly incapable of shame? Is there literally nothing that can shame you?" Power said. "Is there no act of barbarism, no execution of a child that gets under your skin, that just creeps you out a little bit? Is there nothing that you will not lie about or justify?"

Churkin responded to Power's statements, saying she delivered a statement "as if she was Mother Teresa."

"Please remember what country you're representing - remember your own country's track record and then you can start opining from the position of moral supremacy," he said, adding that Russian soldiers "were not observing any abuses of international humanitarian law."

Similarly, Syria's ambassador to the United Nations, Bashar al-Ja'afari also denied reports of mass executions and revenge attacks. However, he emphasized that it was Syria's "constitutional right" to go after "terrorists," referring to all opposition groups.

"Aleppo has been liberated from terrorists and those who toyed with terrorism," Ja'afari said. "Aleppo has returned to the nation."

es,dm/msh (AP, Reuters, dpa)