France condemned on Monday the "deliberate" bombing which killed at least seven people at a hospital in northern Syria administered by the medical charity Doctors Without Borders (DWB), saying such acts "constitute war crimes."

"I condemn in the strongest terms the latest deliberate bombardment targeting a hospital supported by the DWB in northern Syria," said French Foreign Minister Jean-Marc Ayrault. "Attacks against health facilities in Syria, by the regime or its supporters, are unacceptable and must stop immediately. They constitute war crimes," he added.

The United States, which, like the U.N. did not identify those responsible for the air strikes, said two civilian hospitals were hit in and around Aleppo in northern Syria, one run by medical charity DWB and another in the town of Azaz.

Such action "casts doubt on Russia's willingness and/or ability to help bring to a stop the continued brutality of the Assad regime against its own people," the State Department said.

Six patients and one staff member at the hospital died in two separate attacks, the statement said, adding that eight other staff members were still missing and there were tens of people injured.

DWB, which did not attribute blame, confirmed a hospital administered by the charity was hit in Idlib, and said seven people were killed and at least eight were missing, presumed dead.

The British-based monitor Syrian Observatory for Human Rights said the building was destroyed by aircraft that were "presumably Russian."