The US State Department said on Thursday that Syria's air strike on a hospital in Aleppo was "reprehensible," and it called on Russia to use its influence to pressure Syria’s Bashar al Assad to stop the attacks.
State Department spokesman John Kirby said Washington was still learning more about the attack on a hospital supported by the Doctors Without Borders (MSF) medical charity but that there appeared to be several dozen casualties.
"We, obviously, find this attack reprehensible in every possible way. We're looking at dozens, if not several dozens, of casualties in this strike on what was clear that was a medical facility. The details and the circumstances of the attack are still coming in but it sure bears all the hallmarks of the kinds of strikes that the regime has done in the past on treatment facilities and, frankly, on first responders," Kirby said.
"Once again we call on the regime to cease these absolutely senseless attacks, which are of course violations of the cessation of hostilities," Kirby added, calling the bombing "reprehensible."
He said the attack bore the hallmarks of attacks that the Syrian regime has carried out on medical facilities and first responders in the past. Kirby said the Syrian cessation of hostilities was "very much in peril" because of the ongoing violations.
Meanwhile United Nations special envoy to Syria Staffan de Mistura said that he did not believe the targeting of a hospital hit by air strikes in Aleppo overnight was by mistake.
He did not elaborate or comment on who might have been responsible.
The UK-based Syrian Observatory for Human Rights (SOHR) said that fresh air strikes in opposition-held areas of Aleppo, have killed at least 20 people, including three children, on Thursday and the death toll is expected to rise due to the number of serious injuries.
Air strikes overnight on the Medecins Sans Frontieres (MSF)-backed al Quds hospital and a nearby residential building in the opposition-held Syrian city of Aleppo killed at least 27 patients and staff, the SOHR said.
"It is unacceptable, any attack on hospitals is a war crime," the International Committee of the Red Cross spokesman Ewan Watson said in Geneva.