The UN Security Council will hold an emergency meeting on Tuesday to urgently address the crisis in Aleppo following reports that Assad regime forces executed dozens of civilians in the city.
France and Britain requested the meeting scheduled for midday (1700 GMT), diplomats said.
UN humanitarian adviser on Syria, Jan Egeland, said earlier in the day the Assad regime and Russia were responsible for atrocities committed by militias in Aleppo.
"The Gov'ts of Syria & Russia are accountable for any and all atrocities that the victorious militias in Aleppo are now committing!" Egeland tweeted.
Despite Russian assertions last week that the Assad regime would halt attacks on eastern Aleppo to allow civilians to leave besieged areas, Iran-affiliated Shia militias are hindering them from doing so, according to local sources.
- 'People burned alive in their homes'
French Foreign Minister Jean-Marc Ayrault said he received reports of "cold-blooded assassinations of entire families [...] executions, particularly of women and children; People burned alive in their homes; continued targeting of hospitals..."
"Such atrocities revolt consciences. More than ever, there is an urgent need to stop hostilities in Aleppo," Ayrault said in a statement issued Tuesday.
"The supporters of the regime, beginning with Russia, cannot allow this logic of vengeance and systematic terror to be committed [...] without taking the risk of being accomplices," he continued. "I call on the United Nations to use all the mechanisms without delay to establish the truth about what is happening in Aleppo and the international community to ensure that these crimes do not go unpunished."
Ayrault later said his country has again called for a UN Security Council meeting to discuss the situation in Aleppo. "Faced with allegations of atrocities in Aleppo France requested a meeting of the UN Security Council," he tweeted.
Dozens of people condemning what they called silence of the international community in face of what the population of eastern Aleppo is living, gathered on Tuesday afternoon before the French interior ministry in Paris.
"Bashar murderer, your silence make you accomplice", "Putin murderer, Obama accomplice", "Putin murderer, UN accomplice", were thus among the slogans shouted by the protestors.
An estimated 100,000 city residents remain under siege by the regime and its allies in some 8.6 square kilometers of eastern Aleppo.
Over the course of the last 27 days, some 990 civilians have been killed in eastern Aleppo in attacks by the Syrian regime and allied militias, local sources report.
The recent escalation comes amid attempts by the Russia-backed Assad regime to reestablish control over parts of Aleppo captured four years ago by armed opposition groups.
Syria has been locked in a devastating civil war since early 2011, when the Bashar al-Assad regime cracked down on pro-democracy protests -- which had erupted as part of the "Arab Spring" uprisings -- with unexpected ferocity.
Since then, hundreds of thousands of people have been killed and millions more displaced by the conflict.
