Several areas in the Syrian province of Idlib were shelled on Wednesday, with no reports of casualties, only 24 hours after 64 people were killed in air strikes on the rebel-held Syrian city of Idlib on Tuesday, in some of the heaviest raids there in months.

Around eight attacks by unidentified jets wounded scores of people and leveled several multi-storey buildings in residential areas of the northwestern city, they added.

Video footage by activists on social media showed civilians, including young children, being treated in a main city hospital where the injured had been rushed for treatment.

Russian planes have targeted a number of towns and villages in the area since entering the Syrian conflict in September 2015 to back ally President Bashar al-Assad.

But activists and residents also said there had been a reduction of Russian strikes in Idlib province since a Turkish-Russian brokered cessation of hostilities late December.

Planes from the U.S.-led coalition have also launched a number of attacks in the rural province, a major stronghold of jihadists, many of them formerly affiliated to al Qaeda.