Shells fired by Syrian rebel groups are said to have killed at least 30 civilians and wounded 210 others in the northern city of Aleppo.

The rebels have been conducting an intensified shelling against government-held areas of Aleppo since Sunday.

The British-based Syrian Observatory for Human Rights said the Syrian army recaptured several points on Monday that the rebels had taken during their offensive on Sunday.

The group says intense battles are still raging in southern Aleppo. Meanwhile, Russia has announced the establishment of another humanitarian corridor to allow civilians and surrendered rebels to leave Aleppo.