The UN Security Council met for urgent talks on Sunday as Syrian and Russian warplanes pounded rebel-held east Aleppo in the worst surge of bombing to hit the devastated city in years. Britain, France and the United States called the emergency meeting to turn up pressure on Russia and press demands that it rein in its ally Syria to halt the intense bombing campaign on Aleppo.
"War crimes are being committed here in Aleppo," French Ambassador Francois Delattre told reporters, adding: "They must not be unpunished and impunity is simply not an option in Syria."
"Just when we thought things couldn't get any worse in Syria, they have," British Ambassador Matthew Rycroft said.
"The incendiary munitions that are dropping on Aleppo are indiscriminate and a clear breach of international law - the barrel-busting bombs that are falling from the skies likewise," he said.
Residents and a monitor reported heavy air raids overnight and early Sunday on the besieged east of the city, which Syria's army has pledged to retake.
US Ambassador Samantha Power said more than 150 air strikes had hit the city over the past 72 hours. She accused Russia and Syria of launching an "all-out offensive" to re-take Aleppo.
At least 115 people, mostly civilians, have been killed in Syrian and Russian bombardment of eastern Aleppo since the army on Thursday announced an operation to take it, the Syrian Observatory for Human Rights said.
The monitor said at least 19 children were among those killed in the assault, which has included missile strikes, barrel bomb attacks and artillery fire. Residents said cluster bombs rained down on Saturday night on eastern parts of the city, where an estimated 250,000 people are living under a government siege.
"All night long they were dropping cluster bombs. I couldn't sleep until four in the morning," said 62-year-old Ahmed Hajar, who was out looking for bread in the Al-Kalasseh neighbourhood.
"Today the streets of my neighborhood are full of unexploded cluster bombs. One person was killed when he disturbed one and it exploded," he added.
"It tore him apart... it was an awful scene."
In the nearby neighborhood of Bab al-Nayrab, 30-year-old Imad Habush was baking bread in a small wood-burning oven outside his house.
"None of the bakeries are open any more because of the bombing and the shortages of fuel and flour, so people have started making their own bread," he said.
"I don't know why the regime is bombing us in this barbaric way. We're civilians here. We're not carrying weapons, and we're besieged. We have no way to escape."
Air strikes were continuing on the eastern neighbourhoods on Sunday, the Observatory said, with at least 14 civilians, including two children, killed since dawn. Once Syria's economic powerhouse, Aleppo has been ravaged by war and roughly divided since mid-2012 between government control in the west and rebel control in the east. The eastern portion of the city has been under near-continuous siege since mid-July, causing food and fuel shortages.