Site of regime bombing in Aleppo
Site of regime bombing in AleppoReuters

Syria's army on Thursday announced the launch of an offensive to retake the rebel-held east of the battleground city of Aleppo, warning residents to keep away from posts held by anti-regime fighters.

"The military operations command announces the start of operations in eastern districts of the city and calls on residents to stay away from the positions of terrorist groups," it said in a statement carried by state news agency SANA and quoted by AFP.

“Terrorist groups” is the term used by the Syrian regime for all opposition groups.

The announcement came as the United States and Russia convened a last-ditch meeting in New York to save their Syria ceasefire plan and followed several hours of intensive bombardment that left Aleppo in flames.

The army said it would take "all measures to facilitate the reception" of civilians and that those who arrive at its checkpoints would not be arrested.

Heavy clashes gripped the outskirts of Aleppo on Thursday, after air strikes triggered major fires across the city's devastated rebel-held districts.

The Syrian Observatory for Human Rights said that bombardment and air strikes since Wednesday night targeting the rebel-held neighborhoods of Bustan al-Qasr and Al-Kalasseh had triggered "massive fires".

The estimated 250,000 residents of east Aleppo, which rebels have held since 2012, have been living under government siege since early September.

The renewed fighting in Aleppo comes after a truce deal brokered by Moscow and Washington fell apart earlier this week.

The attacks included the bombing of an aid convoy and warehouse belonging to the Syrian Arab Red Crescent, killing around 20 civilians as well as the director of the Red Crescent's Urum al-Kubra branch, Omar Barakat.

AFP contributed to this report.