Years of fighting left rebel-held areas of eastern Aleppo almost completely destroyed. Residents now trapped there say bodies are lying on the streets as people have been too scared of bombing to go out to pick them up. Food supplies have been running very low, and all but the most basic medical facilities are destroyed or out of action.

These pictures from the last few days show the scale of the damage there.

Image source, EPA

Image source, EPA

Image source, Reuters

The head of the Syrian Civil Defense organisation known as the White Helmets says the evacuation process in eastern Aleppo has been suspended because one of their teams was shot at. He says four people were injured.

A truce to allow the evacuation of rebel-held parts of Aleppo has been in effect since 03:00 GMT, according to rebels. There are conflicting details from the ground, but reports suggest that the first ambulances evacuating injured people have turned back following a shooting incident, as BBC's producer Riam Dalati reports.

Reuters news agency reported, quoting a rebel official, that the convoy was hit by militias pro-president Bashar al-Assad.

Syrian Arab Red Crescent ambulances are seen at the Ramouseh crossing in eastern Aleppo, waiting to evacuate wounded and sick Syrians out of besieged areas - in image from the Beirut-based TV station Al-Mayadeen.

Image source, Al Mayadeen / AP

The Syrian Civil Defense emergency response group reports a shooting during preparations for the evacuations.

Doctors Under Fire is trying to evacuate 500 children, many of them orphans. The group's Hamish de Bretton Gordon tells the BBC's World Service he’s just heard from doctors in Aleppo that the children have their bags packed ready to go, and are hoping to get on the buses at about 08:00 GMT.

Russian soldiers are preparing to lead rebels out of Syria's largest city of Aleppo under orders from President Vladimir Putin, Russian state news agencies report.

Rebels and their families will be evacuated towards Idlib, a city in north-western Syria, with drones monitoring the evacuation of 20 buses, accompanied by 10 ambulances, the Russian Defence Ministry is quoted as saying.

Rebel, Syrian military and Russian officials all say an evacuation of rebel fighters, their family members and civilians from the besieged rebel-held section of east Aleppo is about to begin. Welcome to our live coverage.

We are pausing our live coverage of the battle for Aleppo for now. In the meantime, for the latest on the conflict in Syria, read the full story here.

The German foreign minister, Frank Walter Steinmeier, has said it would be a mistake for anyone to believe that the fall of Aleppo will bring an end to the civil war in Syria.

"Probably the war will continue with other methods," he said, adding that there was likely to be "a mix of military confrontations and terrorist attacks" in the country. 

Mr Steinmeier said that despite the events and "atrocities" of recent days in Aleppo making talks more difficult, governments had to find a way back into the political process. There was "no alternative", he said.

The UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, has urged an immediate ceasefire after fighting on Wednesday morning scuppered plans for the evacuation of civilians and rebels in eastern Aleppo.

Mr Zeid said that "snatching" the deal away shortly after it was agreed was "outrageously cruel", adding that the Syrian government had a responsibility to "ensure its people are safe".

"The agreement was there, the buses in place," Mr Zeid said, adding: "This is inexcusable." 

Evacuations were planned for this morning but collapsed after renewed violence, and now the AFP news agency reports that talks have been taking place to save that deal.

An unnamed source told the agency there had been no deal yet, and the talks were focusing on how to evacuate rebels from the area.

There was no mention of whether a deal had been reached for civilians leaving the areas of Aleppo that remain under the control of rebel fighters.

Image source, Reuters

Yesterday, we published a collection of social media messages from people saying their "final goodbyes" as they expected to die.

Today, some of them have been able to tweet again.

Here is an update on those who sent "final goodbyes" while huddled in Aleppo's remaining rebel pockets.

Here's a summary of what's happening in Aleppo:

• Evacuations that were planned for early this morning did not happen because fighting started up again
• The Syrian army blames the rebels for re-starting the fighting, while the rebels blame the Syrians and their Russian and Iranian allies
• Bombs have fallen on east Aleppo and the rebels have fired shells at parts of Idlib province
• The UN says the Syrian government's failure to stick to the ceasefire is "outrageously cruel"
• Turkey and Russia, who brokered the deal, say they are working to get it back on track
• Iran says the deal has to be reciprocal, and wounded people must be evacuated from villages that are surrounded by rebels
• Solidarity actions for  Aleppo have included a march in Sarajevo, Qatar cancelling national celebrations, and the Eiffel Tower 's lights being turned off

Image source, AFP

Image source, Reuters

• US President Barack Obama said in 2012 that his red line with the Assad regime would be the use of chemical weapons
• In August 2013, hundreds of people were killed in a gas attack around Damascus that rights groups and the White House attributed to government troops
• Mr Obama sought congressional approval for military intervention in Syria, but it became clear he would not get it - instead he vowed to pursue diplomacy to remove the regime's chemical weapons
• In the UK, meanwhile, parliament rejected the government's case for possible intervention, voting 285-272 against joining Mr Obama's abortive plan for air strikes
• At the UN Security Council yesterday, representatives from the US and Russia blamed each other for the crisis

Read more from the BBC's Jeremy Bowen about a "blizzard of bitter criticism and recrimination".

Medecins sans Frontieres (MSF) has warned that the situation in Aleppo is "critical" in a string of tweets highlighting the conditions for those who remain in besieged rebel-held areas.

The charity says that heavy shelling has left areas without food or water, adding that people have no access to heaters or electricity. 

People around the world are tweeting their feelings of empathy toward those who remain in eastern Aleppo.

Although a ceasefire was agreed last night, air strikes have been reported again today on rebel-held areas of the city. Evacuations that were planned have not been able to go ahead, and ambulances that were travelling in to the city were forced to turn back.

Karen in Texas, Lisa in Jamaica, Eda in the Netherlands, Mohdi in Kuwait and Amanda in the US tweeted their thoughts about the people who are left in the city.

Image source, Getty Images

Qatar has announced that it is calling off its National Day celebrations next week out of "solidarity with the people of Aleppo".

Usually the celebrations involve a parade and a firework display. They were due to take place on 18 December to mark the 138th anniversary of the founding of the state.

The decision to scrap them came directly from Emir Sheikh Tamim bin Hamad Al Thani.

The day will still be a public holiday. 

The recapturing of Aleppo - the most populous city before the civil war and the country's financial centre - represents a big prize for Syrian President Bashar al-Assad, writes BBC defence and diplomatic correspondent Jonathan Marcus.

Regaining control of the city will be a victory not just for Mr Assad, but also for his Iranian and Russian backers.

But can the Assad government consolidate its hold on Aleppo? What will Moscow want to do next? And what are Washington's options? 

Read Jonathan Marcus's analysis here. 

The BBC has learned that western forces are using satellites and unmanned aircraft to gather evidence of possible war crimes in Aleppo and elsewhere in Syria. 

Government sources said the aerial photographs and satellite imagery would be used to identify potential breaches of international humanitarian law taking place on the ground. 

There have been reports of men and boys being separated from their families in east Aleppo and not being heard of again. There are also reports of civilians being killed deliberately by militias supporting the Syrian government. 

Sources said that as well as using aerial surveillance, Britain and the US were also gathering evidence of alleged atrocities from social media and activists on the ground. 

One government source said: "We want people on the ground to know that if they carry out war crimes, then one day they may get a tap on the shoulder. Nobody will be spared. Justice will catch up with them." 

The Ministry of Defence declined to comment.