Doctors Without Borders said a pediatric clinic in a rebel-held northern Syria province was hit by a series of air strikes over the weekend, killing 13 people.
The international charity, also known by its French acronym MSF, said in a statement on August 8 that two of four air strikes directly hit the hospital in the northern province of Idlib.
It said six other hospital staff members were wounded in the air strikes on August 6.
It was not clear who was responsible and the MSF statement did not specify.
Last month, the United Nations said it recorded 44 attacks on health facilities in Syria.
Syria's government and Russia, a major ally that has been carrying out strikes in Syria since September, deny targeting health facilities.
An MSF-backed hospital in northern Iraq was mistakenly bombed by a U.S. warplane last October, killing 42. The United States later apologized.