If Masaken Hanano district is captured, Bashar al-Assad's regime will be able to retake the entire city of Aleppo.
Syrian regime forces say they have captured the largest opposition-held district in southeastern Aleppo after fierce fighting, but rebels are disputing this, saying that the battle is ongoing.
If Masaken Hanano district is captured, it will be a major breakthrough in the regime's offensive to retake the entire city of Aleppo – Syria's biggest city before the start of civil war in 2011.
Masaken Hanano was the first district opposition fighters took in 2012 in a move that divided Aleppo into an eastern area held by the opposition and a western district controlled by the regime.
More than 250,000 civilians have been trapped under regime siege for months in the opposition-held east, with decreasing food and fuel supplies.
In 12 days since the renewed bombardment by the regime in east Aleppo, more than 500 civilians, including women and children, have been killed.
"The armed forces retook full control of Masaken Hanano after having put an end to the presence of terrorists there," the regime-run broadcaster said, referring to the opposition fighters.
Yasser al-Youssef, from the opposition group's Nureddin al-Zinki, said fighting was still under way on the southern edges of Masaken Hanano, which he called a district of "strategic importance".
Al-Youssef warned that if regime forces advance to the adjacent neighbourhood of Sakhur, then eastern Aleppo will be split into two.
Syrian Observatory for Human Rights, a monitoring organisation based in Britain, said late on Saturday that regime forces now completely controlled Masaken Hanano and had begun an assault on Sakhur and nearby Al-Haidariya.
Families Flee for Safety
The latest regime push comes after days of intense bombardment on the opposition-held east, which was pounded by air strikes, shells and barrel bombs.
The escalation has terrified residents, and several families have fled to areas in southeastern Aleppo which has been relatively calm.
Amid a fierce bombing campaign by the regime and its Russian allies, only three bakeries are left to serve 300,000 civilians in the opposition-held eastern neighbourhoods.
Muhammed Mesleti, a member of Aleppo's pro-opposition local council, told Anadolu Agency that civilians in the city's eastern neighborhoods have been facing hunger.
"The bakeries lack flour and operate every other day until midnight due to the bombardment," Mesleti said.