The World Health Organization condemned Monday's bombing at a hospital in the Syrian coastal city of Jableh, which killed more than 40 people and damaged the facility so much that patients had to be transferred to other hospitals.
The blast was one of several that hit Jableh and Tartus, another government stronghold nearby on Syria's Mediterranean coast. The Islamic State group claimed credit for the attacks.
WHO called the suicide bombing at the Jableh hospital a violation of international humanitarian law and said it is one of at least 17 attacks on health facilities in Syria this year.
"It is unacceptable that such attacks on health are increasing in both frequency and scale," WHO said.
Toll on infrastructure
The United Nations has often cited the toll that Syria's five-year conflict has had on the country's infrastructure, including hospitals and schools. WHO estimates that 60 percent of public hospitals have either closed or remain only partially functional.
The Syrian Observatory for Human Rights, which monitors violence through a network of sources in Syria, said Tuesday that more than 150 people were killed in Monday's attacks.
In this photo released by the Syrian official news agency SANA, Syrians gather in front of a burning car at the scene where suicide bombers blew themselves up, in the coastal town of Tartus, Syria, Monday, May 23, 2016.
Syria's state-run SANA news agency said the Foreign Ministry sent letters of complaint to the U.N. describing the bombings as a "serious escalation" by the governments of Saudi Arabia, Turkey and Qatar. It said those countries want to undermine efforts to halt the violence in Syria.
Since the conflict erupted in March 2011, the Syrian government has often pointed to outside influences as driving the violence and cast any opposition fighters as "terrorists."