Syrian Civil Defense rescuers run from the site of a second explosion near a Doctors Without Borders hospital in Syria on Monday.

According to the United Nations, as many as 50 people were killed in northern Syria on Monday when four hospitals—including a Medecins Sans Frontieres (Doctors Without Borders) facility in Maarat al-Numan—were bombed. “Such attacks are a blatant violation of international laws,” the UN said.

France said the attacks constituted war crimes. MSF said that its hospital was hit by four missiles in quick succession, saying that it “wasn’t an accidental attack, that it was deliberate.” Seven people died in that attack. Eight are still missing. From the BBC:

Mego Terzian, president of MSF France, told Reuters “either the [Syrian] government or Russia” was “clearly” responsible.

But the Syrian ambassador to Moscow Riad Haddad, said the US was to blame, a claim the Pentagon dismissed as “patently false”.

“We have no reason to strike in Idlib, as Isil [Islamic State] is not active there,” spokesman Capt Jeff Davis said.

Russia maintains that it only targets “terrorists.” A U.N. spokesman, Farhan Haq, told the New York Times that two of the hospitals contained pediatric and maternity wards supported by Unicef, and that the 50 people killed on Monday included children.

According to Physicians for Human Rights, 697 health care workers have been killed in 336 attacks on medical sites since the Syrian conflict began. On Monday, Russia’s Ministry of Foreign Affairs said it would continue airstrikes against rebel positions even if a proposed cease-fire goes into effect.

Image via AP. Contact the author of this post: brendan.oconnor@gawker.com.