An AFP news agency correspondent in government-controlled western Aleppo says there have been no sounds of fighting or bombardment since around 15:00 (13:00 GMT) on Tuesday. 

The Syrian Observatory for Human Rights, a UK-based monitoring group, is also reporting that there has been calm in recent hours.

Staffan de Mistura also said the UN would like to be present when the evacuation of civilians from eastern Aleppo takes place, and when the armed opposition withdraws. 

"We are insisting that civilians who may want to go with them - people like volunteers - should also be allowed to do so,” he added. 

Image source, European Photopress Agency

The UN special envoy to Syria, Staffan de Mistura, also admitted that he had “no evidence” to back up reports, external that tens of civilians have been summarily killed by advancing Syrian government forces in eastern Aleppo in the past 24 hours. 

The Syrian army has insisted the allegations are false, but the UN envoy noted: “The fact is that there are bodies in the streets and the squares, including obvious civilians like women and children.”  

Just to give you some background, Aleppo was Syria's largest city and its commercial and industrial hub before the uprising against President Bashar al-Assad began in 2011.

It became a key battleground in the civil war in 2012, when it was divided roughly in two, with the government controlling the western half and the opposition the east.

Troops broke the deadlock this year with the help of Iranian-backed militias and Russian air strikes, reinstating a siege on the east in early September and launching an all-out assault weeks later.

Image source, Reuters

The government stepped up its offensive in mid-November after a three-week pause in air strikes to allow civilians and rebels to leave - an opportunity few took up.

The rebel’s defences subsequently collapsed and by Monday the government had recaptured more than 90% of the east.

You can read more about the battle here: 

What's happening in Aleppo?

Zouhir al-Shimale, a freelance journalist based in eastern Aleppo, has been tweeting, external about the news of the ceasefire deal.

The UN special envoy to Syria, Staffan de Mistura, has just been briefing reporters.

He said the situation in eastern Aleppo is still "very concerning".

Although UN officials are not on the ground there, he estimates that the area still under control of armed opposition groups is probably only four to five square kilometres (1.5-1.9 sq miles).

Image source, AFP

There could be up to 50,000 civilians there, he adds, along with some 1,500 fighters. He estimates that about 30% of them are members of Jabhat Fateh al-Sham, a jihadist group that was known as al-Nusra Front until it broke off formal ties with al-Qaeda earlier this year.  

As rebels are pushed out of eastern Aleppo, one resident explains why many civilians are unable to escape.

A Syrian journalist and activist based in eastern Aleppo, Rami Zien, spoke on Periscope about an hour ago. 

"What we have seen in the past two days is indescribable," he said. 

"We are hoping that the agreement about the evacuation of the city and the fighters will be implemented, so we can all go safely." 

Viewers in the UK will be able to catch a special edition of Newsnight on Aleppo in the coming hours. 

Russia's permanent representative to the UN, Vitaly Churkin, says that "according to the latest information that we received in the last hour, military actions in eastern Aleppo are over". 

As a result, "there is no issue of some cessation of hostilities, or some special humanitarian operation", he adds. 

"The Syrian government has re-established control over eastern Aleppo."

Key dates in the battle for Syria's second city, held by rebels since 2012.

In the hours before rebels prepare to leave besieged Aleppo, thousands of citizens remain trapped.

A spokesman for the Nour al-Din al-Zinki rebel group tells AFP news agency that the deal was "sponsored" by Russia and Turkey, which backs the opposition, and will be implemented "within hours". 

The first stage will see the evacuation of civilians and wounded, Yasser al-Youssef says. Then, rebel fighters will leave with their light weapons, he adds. 

A source in the powerful Ahram al-Sham faction also confirmed the agreement, according to AFP. 

Image source, ITN

British Foreign Office minister Tobias Ellwood has said the United Nations has been cranking up the pressure on Russia to agree to a ceasefire and if this does not work, "other options" will have to be considered such as further sanctions.

Following the debate earlier, Mr Ellwood said it was clear that the UK Parliament wanted to do more but that some proposals being put forward - such as aid drops - were "very, very dangerous" and that the Commons was "haunted by interventions in Iraq and Afghanistan" as well as the 2013 vote in which it rejected the case for military action against the Assad regime.

A Syrian military source tells Reuters news agency that evacuations of rebel fighters will begin at 05:00 local time (03:00 GMT) on Wednesday. 

The source adds that they would leave towards the countryside west of Aleppo, parts of which are controlled by rebel groups.  

It is not yet exactly clear what the ceasefire deal entails. Addressing the UN Security Council, Russian permanent representative Vitaly Churkin said the military operation in Aleppo would end "in the next few hours". 

"All militants, together with members of their family and the injured, currently are going through agreed corridors in directions that they have chosen themselves voluntarily," he added.

A member of the White Helmets in Aleppo speaks to BBC Newsnight with government forces just 300m away.

Good evening and welcome to our coverage of the announcement that the Syrian government has agreed to a ceasefire deal that should see rebel fighters leave besieged eastern districts of Aleppo, ending a four-year battle for control of the city.