International medical aid group Doctors with Borders (MSF) said Thursday that the hospitals it supports in Syria have been attacked 101 times since the start of last year.
"Today in Syria, the abnormal is now normal. The unacceptable is accepted," MSF president Joanne Liu said at the group's headquarters in Geneva, calling for an immediate end of attacks on civilians and health infrastructure.
"Permanent members of the UN Security Council, four of whom are actively involved in the war in Syria, must answer for their failure to uphold their most basic responsibilities toward civilians," said Liu.
The head of MSF was pointing to the United States, France and Britain, which are allies in fighting the Islamic State extremist group, as well as Russia, which backs Syrian government forces.
On Monday, 25 people were killed in an airstrike that destroyed a hospital supported by MSF south of Aleppo.
Western governments have accused Russia of carrying out this strike, but Moscow has denied responsibility.
A dozen MSF-supported hospitals were destroyed and 25 staff members were killed in bombings and shellings last year.
"The doctor of your enemy is not your enemy," Liu said.
The Syrian government banned any health facilities in rebel-held areas since 2012. MSF-supported clinics have therefore been operating in clinics.