Government takes two key neighbourhoods as bombing raids on rebel areas intensify in and around the major city.
The Syrian army has said it had captured two districts of the rebel-held eastern part of Aleppo city in two days, as government air raids continued to target opposition-held parts of the country.
The army said it and its allies had taken full control of the Jabal Badro and Baadeen districts on Sunday, a day after capturing Hanano, a neighbouring residential district.
The fighting has now moved to neighbouring districts, including Haidariya and Sakhur.
Aleppo, which was Syria’s biggest city before the start of a civil war that has killed hundreds of thousands of people, is divided between the government-held west and rebel-held east, where UN officials say at least 250,000 people remain under siege.
The capture of Jabal Badro came as opposition activists reported tens of civilian casualties from a presumed government or Russian bombing raid on a village outside Aleppo.
The Local Coordination Committees activist network reported 15 civilians were killed and tens mroe wounded in a Russian air raid on the rebel-held village of Anjara on Sunday.
READ MORE: Inside east Aleppo’s last hospital - ’No space to walk’
The opposition usually identifies planes by their silhouettes and home base.
The Britain-based Syrian Observatory for Human Rights, which relies on a network of informants in Syria to monitor the war, said the attack was accompanied by raids on other opposition-held villages in the Aleppo countryside.
Al Jazeera’s Osama bin Javaid, reporting from Gaziantep on the Turkey-Syria border on Sunday, said a Syrian government strategy of using "brute force seems to be working."
He added that the fall of Jabal Badro and Hanano could have a "domino effect" on other parts of the besieged city.
As the government offensive continued in opposition neighbourhoods of the city, around 400 people have fled to areas under government control, the monitoring group said on Sunday.
An additional 30 families fled to Sheikh Maqsoud, which is under Kurdish control, it added.
Syrian state media also reported that hundreds of families had vacated areas under rebel control.
Al Jazeera’s bin Javaid said civilians continued to pour out of the besieged part of the city.
"Thousands have fled the Hanano neighbourhood and other areas near the frontlines towards the central parts," he said. "But the air strikes in the last 13 days have relentlessly targetted anything that moves, be it ambulances or rescue workers. Hospitals have been destroyed and people have very little food and medicine."
’Too many are dying’
Capturing all of Aleppo would be a major victory for Syrian President Bashar al-Assad after five and a half years of fighting.
The Lebanese Al-Manar TV channel reported from Aleppo on Sunday morning, showing workers and soldiers clearing debris against a backdrop of bombed-out buildings on both sides of the street.
Al-Manar is a media outlet affiliated with Hezbollah, a Lebanese armed group aligned with the Syrian government.
The UN’s children’s agency (UNICEF) warned on Sunday that nearly 500,000 children were now living under siege in Syria, cut off from food and medical aid, mostly in areas under government control.
That figure has doubled in less than a year, UNICEF said, and many are now spending their days underground, as hospitals, schools and homes remain vulnerable to aerial bombardment.
"Children are being killed and injured, too afraid to go to school or even play, surviving with little food and hardly any medicine," UNICEF Executive Director Anthony Lake said.
"This is no way to live — and too many are dying."