ALEPPO, Syria – Bebars Meshall is frantically putting out a fire in eastern Aleppo, but it’s already too late. The rebel-held side of Syria’s largest city has lost yet another hospital to Syrian government airstrikes.

There are only one or two fully operational hospitals left in eastern Aleppo, Meshall, a member of the volunteer first responder group Syria Civil Defense, told Syria Deeply. “We can only hope that they won’t get targeted.”

For four years, Syria’s largest city has been a battlefield torn between armed opposition factions in the east and government forces in the west. In February, the Syrian government launched a new offensive to take back the east of the city, prompting fierce retaliation from opposition factions. Forces loyal to Syrian president Bashar al-Assad’s government used warplanes, barrel bombs and snipers, destroying eastern Aleppo’s infrastructure and healthcare system in the process.

As of April 2016, there have been 365 attacks on medical facilities in Syria and 738 healthcare workers have been killed, according to data from the global nonprofit Physicians for Human Rights (PHR). More than 90 percent of those attacks are attributed to the Syrian government and its Russian backers, and some 96 attacks were carried out in Aleppo.

Roughly 95 percent of the once-thriving city’s doctors have fled, been killed or detained. This has led to an extreme shortage of staff – particularly specialized physicians. General surgeons, he said, are forced to do the work of neurosurgeons, oncologists, endocrinologists and vascular surgeons.

“It’s a struggle for us to treat our patients, to provide them with the care that they need,” said Dr. Abu Sayed, a physician working in Eastern Aleppo.

Dr. Sayed said his facility receives between 15 and 20 war injuries a day, mostly civilians, and often children. But without a pediatrician on staff, children have to be treated by non-specialized physicians. (Dr. Sayed asked that his facility not be named for security reasons.)

In April, a Syrian government airstrike on the eastern al-Quds hospital killed one of the rebel-held Aleppo’s last pediatricians, Dr. Muhammad Waseem Maaz. The hospital was supported by Medecins Sans Frontieres (MSF) and was one of the few left in Syria with a functioning emergency room, intensive care unit and operating room.

Healthcare in eastern Aleppo has only gotten worse after Russia intervened on behalf of the Syrian government in September 2015. A report by Amnesty International called out against the systematic targeting of hospitals and medical facilities in Aleppo by Syrian and Russian forces, a violation of international humanitarian law.

“But what is truly egregious is that wiping out hospitals appears to have become part of their military strategy,” said Tirana Hassan, crisis response director at Amnesty International.

The estimated 300,000 people who still live in the opposition-held parts of Aleppo are now effectively under siege. An advance by the Syrian government on Thursday has left the only road in and out of the city within firing range, cutting off eastern Aleppo’s last supply route. Elise Baker, research coordinator at PHR, said healthcare in Aleppo has never been more limited, with no way for health workers or aid deliveries to enter.

“In the meantime, the city’s few remaining understaffed and undersupplied medical facilities continue to be bombed, damaged and destroyed,” said Baker. “The doctors who survive these attacks are forced to literally rebuild their own hospitals if they have any hope of saving lives.”