Syrian government attacks on hospitals in Aleppo have devastated the frontline city’s health care, with roughly 95% of doctors having fled, been detained or killed, Physicians for Human Rights said Wednesday.

Less than a third of city’s hospitals are functioning as a result of 45 attacks in the past three years, said the rights group in a new report.

“The Syrian government is using attacks on Aleppo’s health care system as a weapon of war,” said Michele Heisler, one of the authors of the report.

Aleppo city has been divided between government forces that hold the west and rebels controlling the east since shortly after fighting began there in mid-2012.

Syrian government forces backed by Russian airpower are making a new push for full control of Aleppo and seized the town of Al-Hader south of the city earlier this month.

The New York-based rights group said they had documented at least 10 Russian air attacks on medical facilities in October and that one medical worker had died in a strike.

Hospital staff evacuated newborns from incubators when Russian air strikes hit the Al-Hader hospital on October 16, according to the report.

The rights report said there were fewer than 80 physicians working in Aleppo throughout any given month, or about 5% of Aleppo’s pre-war physician population.

Syria’s nearly five-year war has left more than 250,000 dead and forced some 12 million people from their homes.

AFP contributed to this report.