Almost 50 people have been killed, while others are missing after air strikes in Syria’s Azaz and Idlib that hit two schools school and “at least five” hospitals.

One of the hospitals targeted was run by Medicins Sans Frontieres (MSF), witnesses say, while another had its maternity ward hit.

A medic and two residents initially said 14 people were killed by missiles at a children’s hospital and a school where refugees fleeing a major Syrian army offensive were sheltering in Azaz, a rebel-held town near the Turkish border.

• The latest Apple prank that will kill your iPhone
• ‘Trickery’ used to deceive shoppers over health stars
• Past lessons are haunting the PM of the present

In a separate attack, at least seven people were killed and eight are reportedly missing after an attack on an MSF hospital in Idlib, in northern Syria.

“There were at least seven deaths among the personnel and the patients, and at least eight MSF personnel have disappeared, and we don’t know if they are alive,” MSF France president Mego Terzian said.

“The author of the strike is clearly … either the government or Russia,” he said, adding that it was not the first time MSF facilities had been targeted in the country.

The death toll is said to have risen significantly, though, with United Nations Secretary-General Ban Ki-moon saying close to 50 had been killed.

An Azaz resident said another refugee shelter south of the town was also hit by bombs dropped by jets believed to be Russian.

“We have been moving scores of screaming children from the hospital,” medic Juma Rahal said.

The U.N. confirmed that victims of the attacks included children.

Ban-Ki moon was quoted as saying the attacks were “blatant violations of international laws”.

Tens of thousands of people have fled to the town of Azaz, the last rebel stronghold before the border with Turkey, from towns and villages where there is heavy fighting between the Syrian army and militias.

Independent Doctors Association, a Syrian non-government organisation that runs a hospital in Bab al Salama near the Turkish border, said at least 30 people were wounded.

MSF said its hospital was destroyed after being hit by four missiles following two attacks within a few minutes interval.

“This is a deliberate attack against a health establishment,” Massimiliano Rebaudengo, MSF head of mission, said.

“The destruction of this hospital deprives about 40,000 people of health care in this conflict zone.”

The hospital, which has 54 staff and holds 30 beds, is financed by the medical charity.

MSF also supplies medicines and equipment to the facility.