'The Whole World Has Abandoned Us': Aleppo Doctors Fight for Patients' Survival “Yesterday, we escaped death,” said a nurse working inside the conflict zone.

 LONDON -- Medical personnel inside the besieged city of Aleppo say they have come under attack as an onslaught by government forces backed by Russian air power has pushed deeper into rebel-held territory.

“Yesterday, we escaped death,” a nurse working in east Aleppo told ABC News. The woman, Baraa, who didn’t give her last name, said that she was working on a child’s leg wound on Sunday when her clinic was hit by an airstrike.

“The bombardment started above us like rain,” she said, adding that she ran away from the strikes with some of her friends at the clinic. The child she was treating had been wounded from another airstrike and brought to the clinic for treatment.

“While I was stitching him a brutal airstrike happened. The electricity shut down,” Baraa said. The child is wounded, but not in danger, she said.

Airstrikes continued to pound east Aleppo on Monday and intense clashes broke out in the al-Shaar neighborhood, where Syrian government troops advanced, according to the Syrian Observatory for Human Rights.

The brutal fighting has killed dozens in the past few days, the Observatory said, even as U.S. and Russian diplomats worked on a possible deal for rebels to leave contested areas of the city.

U.S. Secretary of State John Kerry said he planned to meet this week in Geneva with Russian Foreign Minister Sergei Lavrov to discuss a proposed withdrawal of all rebels from east Aleppo.

Lavrov told a news conference on Monday that rebels who stay in that area will be treated as terrorists once a deal is reached.

"We will treat them as such, as terrorists, as extremists, and will support a Syrian army operation against those criminal squads," the Russian official said.

Anas Moughrabieh, a doctor in Michigan with the Syrian American Medical Society, said nurses inside Aleppo have been calling him to say goodbye. A few days ago, he said some nurses tried to reopen east Aleppo’s M2 hospital, which had been out of service. They consulted with him about two patients over the phone.

“One made it to life and the other one was moderately sick,” he said over a messaging app. “I asked them to prematurely give up on the sicker one and I felt bad to tell them it is a luxury now to care for patients with this level of illness with this limited resources. They didn't give up on him until their location was discovered and attacked with barrel and cluster bombs.”

Hamza Khatib, a doctor in east Aleppo who uses a pseudonym, said the hospital where he works has been receiving more than 300 injured people every day.

“The situation is madness,” Khatib told ABC News. “We have lost a lot of lives, most of them are civilians. Now, the regime has managed to take a part of the already besieged city, and a lot of people are crowded in a smaller area. That means that each rocket, each missile will produce a bigger amount of injuries and death.”

He said he had been in east Aleppo since 2012 and the current offensive on the besieged city is the worst he has ever seen.

“We are under attack,” the doctor said. “We have the feeling that the whole world has abandoned us, left us here in Aleppo to be killed brutally with no help at all. We can’t defend ourselves. We can’t do anything. We can’t protect our hospitals. We can’t protect our lives. We can’t protect our patients’ lives. We can’t protect our families’ lives. It’s desperate here.”

Syrian government forces and rebels faced off in explosive battles in east Aleppo’s al-Zebdieh neighborhood Monday as the Syrian government forces attempted to advance, the Syrian Observatory said. Abdulkafi Alhamdo, a teacher in al-Zebdieh, said his neighborhood was shelled approximately 100 times in half an hour.

“A massacre maybe just 50 meters away from my house, people on the ground,” he said, adding that some people who came to the area to help were injured when more bombs hit. “No cars dare to come to help them. It’s horrific,” he said.

East Aleppo hasn't received United Nations aid since July. Residents live with little access to water, food, health care or fuel for heating.

Some of the people who left east Aleppo neighborhoods that have been seized by the government have moved into Alhamdo's building. One of them, a child, knocked on his door, he said.

"He was holding a jug, asking me for clean water, even a cup for his little sister and asked me for a bottle of water just to clean the cups. He said, 'Uncle, I know we are disturbing you with our requests but what should we do?'"

The boy nearly broke out in tears as he thanked Alhamdo before returning to his family with two bottles of water, Alhamdo said.