Add a lack of hospitals to the list of tragedies affecting civilians who live in rebel-held Syrian city of Aleppo. The latest week-long bombing campaign carried out by Syrian and Russian forces has disabled nearly all the remaining medical facilities in the eastern part of the city, according to the World Health Organization, leaving only a few small clinics.

This development means an estimated 250,000 civilians are almost entirely without access to medical care as the Syrian government continues to push into Eastern Aleppo, killing scores of civilians in an effort to reclaim control of the city. One of the last remaining facilities in the city, as of Monday, is seeing 350 to 400 injured people each day, a doctor told ABC News.

"As of yesterday, there are barely any functional hospitals left in eastern Aleppo able to treat those who have escaped death as all the hospitals are being bombed into oblivion," the United Nations' Stephen O'Brien wrote in a letter Monday. "Let me be clear: we are not just seeing a resumption of violence in Aleppo, this is not business as usual. What has been unleashed on civilians this past week is yet another low in an unrelenting inhuman onslaught, and it is as heart-breaking as it is not inevitable."

Health officials told Al Jazeera they suspect military forces are targeting them "to make people give up." At least two hospitals came under "intense shelling by the regime" in the last week alone.

"Although some health services are still available through small clinics, residents no longer have access to trauma care, major surgeries, and other consultations for serious health conditions, despite urgently needing this care," WHO reported on Sunday. "This further suffering is imposed on a population that has had only precarious and steadily declining access to health care for the past five years, as the conflict has brought relentless damage and destruction to health facilities."

The situation is especially dire considering the fact that aid groups have been unable to enter the city to deliver medical resources since July. Limited supplies and space at medical facilities have contributed to high mortality rates, as ATTN: previously reported.

With a declining number of medical facilities and doctors, the humanitarian crisis is escalating for the approximately 250,000 people who remain inside the war-torn city — including about 100,000 children, according to The New York Times' Rick Gladstone.

"Aid groups estimate that there are only 35 doctors remaining in East Aleppo — one for every 7,143 people, assuming a population of 250,000 people," the Times reported in September. "By comparison, in New York — which has the worst doctor-patient ratio of any American city — it is one for every 912 people. However, some groups say the population of eastern Aleppo is much lower, in the tens of thousands."

In light of the attacks, medical workers have been moving patients and supplies underground, but the intensity of the bombing campaigns has even compromised many of those makeshift treatment facilities. One video circulating social media this week, provided by Syria Charity, an aid group, captures this traumatic effect of the civil war: a boy being treated after he inhaled toxic fumes from a gas bomb that reportedly struck a children's hospital he was staying at over the weekend.

"You can’t imagine what it’s like living in Aleppo right now," Dr. Omar, one of the last doctors stationed in Aleppo, told the Times.

"It feels like we are living in hell," Omar said. "Our neighborhoods are in flames, and bombs are raining down from the sky. We urgently call on the international community to send help."