A major development in central Aleppo -- as Syria's army has regained control of a rebel-held district, after days of heavy air strikes.

Pro-government troops seized the Farafira district northwest of Aleppo's historic citadel in a ground advance on Tuesday.

The Syrian military, helped by Iranian-backed Shi'ite militias and the Russian air force, launched a campaign to retake Aleppo last week. This latest offensive comes after a US-Russia brokered ceasefire deal collapsed.

UK-based monitor Syrian Observatory for Human Rights said more than 165 people have been killed by bombardments since.