Syrian government forces swept through the old city of Aleppo as rebel forces - besieged and facing certain defeat - debated when to withdraw from their shattered stronghold.
The army and allied militiamen now hold three-quarters of east Aleppo, four years after the area fell from government control.
The Syrian Observatory for Human Rights, a monitoring group, said forces allied with Syrian President Bashar al-Assad took over the old city after rebels withdrew south into what remains of their territory.
As the United States and Russia prepare talks on the prospect of a rebel withdrawal, the militants themselves now seek escape. They called for civilians to be allowed to leave for the northern countryside during a five-day ceasefire.
But officials within the armed opposition, said a much broader agreement was in the cards involving full withdrawal from what was once their most important stronghold. Activists said dozens of rebels had already fled.
In 2012, the capture of east Aleppo was seen as one of the rebels' biggest victories. It turned out to be a fatal overstretch, making this final confrontation for the former commercial capital inevitable. The eastern districts have been under siege since July while Syrian and Russian warplanes have launched rounds of bombardment, killing hundreds of civilians and destroying hospitals. More than 730 people have been killed in Aleppo since the start of a November 15 government offensive and 80,000 have fled, the Syrian Observatory added yesterday.
Repeated government warnings - sent via text message or printed on airdropped leaflets - have urged residents to leave, warning that those who stay would be "annihilated".
The recapture of Aleppo would mark Assad's greatest victory in Syria's five-and-a-half-year war. In comments published yesterday, the Syrian President said victory in the Aleppo would be a "huge step" towards the end.
But it comes at a huge cost. Thousands of civilians have been killed, and the recaptured districts lie in ruins, their apartment blocks shredded and infrastructure destroyed.
History has also been erased. The 14th century Old Souk has burned, and at the Umayyad Mosque, metal spikes twist out where a minaret once stood.
Inside what remains of the rebel enclave, there is a growing humanitarian crisis. Amid blistering bombardment, thousands of residents displaced by the offensive now shelter inside abandoned apartment blocks. Food has almost run out, and fuel stocks are so low rescue workers are often unable to reach the wounded.
"Even by Syrian standards, the recent bombardment and shelling have been the most intense in Aleppo," said Hanaa Singer, Unicef's representative in Syria.