Government air strikes have resumed in rebel-held Aleppo, says the Syrian Observatory for Human Rights, a UK-based monitoring group.

Rebel shellfire has killed at least six people in government-held areas of Aleppo since Wednesday morning, Syrian state television reports.

Several other people have been wounded, it says.

Victoria Derbyshire

Earlier on Wednesday, rebel-held areas were reportedly shelled by government forces.

Activist Monther Etaky blamed both Iran and Syria for the violence, telling the Victoria Derbyshire programme: "We are under a genocide". 

During the interview, loud bangs could be heard nearby, which Mr Etaky said had been continuing for three hours.

When asked if he needed to flee, he said: "It's not a problem. We are used to that."

Fighting has reportedly broken out again in Aleppo.

An AFP news agency correspondent inside the rebel enclave reports seeing several wounded civilians after an area was hit by tank fire. 

The Syrian Observatory for Human Rights, a UK-based monitoring group, says the clashes are "violent" and that the bombardment is "very heavy". 

"It seems as though everything [the ceasefire] is finished," its director, Rami Abdul Rahman, tells the Reuters news agency.

Image source, AFP

BBC Arabic's Assaf Abboud cites Syrian army sources as saying that the implementation of the Aleppo ceasefire and evacuation deal requires rebel fighters to release captured Syrian soldiers and to return the bodies of any dead soldiers. 

The government also wants rebel groups to lift their sieges of the pro-government Shia towns of Foah and Kefraya, in Idlib province, according to the sources.

Our correspondent believes these such terms will necessitate lengthy negotiations and mean it is unlikely the evacuations will start on Wednesday.

Image source, AFP

Turkey is talking to Russia and Iran to try to ensure the ceasefire in Aleppo holds and that civilians and rebel fighters can be evacuated, Turkey's foreign minister says. 

"There was an understanding as of yesterday, and within that was first the evacuation of civilians ... we see that the regime and other groups are trying to prevent this," Mevlut Cavusoglu tells reporters in Ankara. 

"We are continuing our meetings. We will speak with [Russian Foreign Minister Sergei] Lavrov and the Iranian foreign minister again today," he added. 

Mr Lavrov has accused rebel fighters of breaching the ceasefire.

Salah Ashkar, an activist and journalist in Aleppo, says his building was hit by government fire earlier on Wednesday. 

In this video, he says a group of people who were waiting for the buses to evacuate them "had to run for their lives and find shelter".

Today Programme
BBC Radio 4

Brothers Wissam and Zane are inside a busy shelter in rebel-held eastern Aleppo, waiting to be evacuated. 

Their mother told the Today programme that they were "terrified" and pleaded with the international community to help them get out. "Please help us," she said. 

Two months ago, Wissam and Zane told Today about their lives under siege.

The Associated Press cites media reports as saying that buses which have been on stand-by to evacuate people from rebel-held Aleppo are returning to their depots.

Image source, Getty Images

Brian Bilston, the accidental poet of Twitter, is known for his humorous take on everyday life. But on Wednesday he wrote a poem called "O Little Town of Syria".

He called it a "Christmas carol" for Aleppo.

A spokesman for the Syria Civil Defence, whose rescue workers are commonly known as the White Helmets, tells the BBC that there was "very heavy" shelling of rebel-held districts on Wednesday morning.

Various weapons were used and more than 40 people were injured, Ibrahim Abu Laith says. 

Earlier, the head of the Syria Civil Defence, Raed al-Saleh, tweeted this:

Lina Shamy, an opposition activist in rebel-held Aleppo, is accusing the government and its ally, Iran, of breaking the ceasefire agreement.

Yesterday, she made an impassioned plea to the world to "save Aleppo."

A journalist based in the rebel enclave says people there do not know what to make of the fresh fighting.

Russia's defence ministry says rebel fighters opened fire at coaches that were meant to evacuate them on Wednesday morning.

"The militants' withdrawal was planned for about 06:00 local time by coaches along a corridor in the Salahuddin neighbourhood," a ministry statement is quoted by the Interfax news agency as saying. 

"After the transport arrived at the agreed embarkation point, militants opened fire at the convoy."

Russia's Interfax news agency cites the Russian defence ministry as saying "militants resumed fighting" in Aleppo at dawn. 

Their attack was "repelled" and the Syrian army is continuing the operation to "liberate the remaining parts of the city", it adds.

Russia, which backs the Syrian government, now says it could take up to three days to resolve the Aleppo situation.

"I expect that the rebels will cease resistance in the next two to three days," Foreign Minister Sergei Lavrov told Russian media. 

Evacuations of rebel fighters were originally planned to begin early Wednesday morning.

Mr Lavrov also called talks on Syria between Russia and the United States - which supports the opposition - a "fruitless talking shop", according to RIA news agency.

A civilian witness tells the Reuters news agency that the government shelling of rebel-held Aleppo stopped after about half an hour.   

Activists tell the BBC that the Ansari and Mashhad districts were hit about 15 minutes ago, and that civilian casualties have been reported.

Zouhir al-Shimale, a freelance journalist based in eastern Aleppo, has posted a video he says shows that government forces have resumed their artillery bombardment of the besieged rebel enclave.

The pro-opposition Qasioun News agency is reporting that Iranian-backed militias have violated the ceasefire.

Russia - whose air strikes helped Syrian government forces break four years of deadlock in Aleppo - says 5,990 civilians, among them 2,210 children, have fled rebel-held districts of eastern Aleppo over the past 24 hours. 

Over the same period, 366 rebels laid down their arms and moved into government-controlled areas, it adds.