Beirut: Air strikes on Monday destroyed a hospital in northwestern Syria supported by Doctors Without Borders (MSF), killing at least seven people and leaving more missing, the group said.

The Syrian Observatory for Human Rights, a Britain-based monitor, said the raids were believed to have been carried out by Russian warplanes.

MSF did not assign blame for the attack, but said another eight people were missing, presumed dead, in the incident.

It said the dead included five patients, a caretaker and a hospital guard, and that the missing eight were all staff members.

An unknown number of patients were also missing, the group added.

Earlier, the Observatory said nine people, including a child, had been killed in the strikes near Maaret al-Numan in the northern province of Idlib.

The raids also left dozens wounded, added the monitor, which relies on a network of sources on the ground.

MSF said four rockets had hit the 30-bed facility, which had 54 staff, two operating theatres, an outpatients' department and an emergency room.

"This appears to be a deliberate attack on a health structure, and we condemn this attack in the strongest possible terms," said Massimiliano Rebaudengo, the head of MSF's Syria mission.

"The destruction of the hospital leaves the local population of around 40,000 people without access to medical services in an active zone of conflict," Rebaudengo said.

The organisation supports around 150 hospitals in Syria.

Russian warplanes have conducted air strikes in Syria since September 30 in support of President Bashar al-Assad's forces.

The Observatory says it determines whether strikes were carried out by Syrian, Russian or US-led coalition aircraft based on the location of the raids, flight patterns and the types of planes involved.