DAMASCUS, May 30 (Xinhua) -- As many as 71 people were killed by Syrian aerial bombardment on militant-held areas in the country's northern city of Aleppo, a monitoring group said on Saturday.

Syrian helicopters dropped crude barrel bombs on the al-Sha'ar neighborhood in Aleppo, killing 12 people and injuring 15 others, said the Syrian Observatory for Human Rights.

The UK-based watchdog added that another 59 people were killed by similar bombing on the al-Bab city, which is controlled by the Islamic State (IS) militants in the countryside of Aleppo.

The death toll could rise due to the large number of critically wounded people, it added.

Aleppo, Syria's second largest city, has been carved out between the rebels and the government troops. Huge destruction has befallen that important city, which was once the economic capital of Syria.