As the Syrian government army makes advances in east Aleppo, civilians say the situation is getting worse.

Residents in rebel-controlled east Aleppo – now down to a handful of neighbourhoods – say they fear retribution if they flee to government-held areas.

Aisha, a mother of three children, is one of them.

Last week, she and her family fled farther south in Aleppo when government forces took over her neighbourhood. Despite the bombings, weak utilities and sanitation, and depleting food supply, Aisha says she prefers to live in rebel areas.

“We’re hearing about the army taking and arresting people, so I’m content to wait for a route to open so I can go to live with my family in the countryside,” she said. On Friday, hundreds of men from Aleppo went missing after entering government territory, including some of Aisha’s family members with whom she lost contact.

After the military onslaught that began three weeks ago, the Syrian army is now controlling around 85 percent of previously rebel-held parts of east Aleppo. The UN and rebel sources say 100,000 people are now in east Aleppo, crammed into a handful of neighbourhoods that amount to around 15 percent of the area the rebels held three weeks ago.

Jasim, another east Aleppo resident, says he fled from his neighbourhood now under Syrian army control. “When we left the neighbourhood, the bombing was all around us, and we couldn’t take anything with us except for the clothes we could carry,” he told Al Jazeera.

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We went from street to street and the sound of bullets doesn't stop. There was no one else but us on the street. I can't risk something happening to my children by leaving. There's bombing happening… throughout the day and night. Aisha, east Aleppo resident

Civilians still trapped in rebel-controlled parts of the city say they are facing immense hardships, especially those who recently fled the army’s advance. “We don’t know how to sleep or eat. I don’t have anything with me, just a little money,” said Aisha, who claims to have walked to her current location.

“We went from street to street and the sound of bullets doesn’t stop. There was no one else but us on the street.”

The fear of violence keeps Aisha and others from leaving east Aleppo altogether. “I can’t risk something happening to my children by leaving. There’s bombing happening … throughout the day and night,” said Aisha, referring to Syrian army air strikes.

The UN also said it heard reports of rebel groups preventing some civilians from leaving for government areas.

According to Ismail Abdullah of the Syrian Civil Defence – aka the White Helmets – the residents who remain in the city are civilians and fighters. “Most of them are families, and women and children. A lot of them are families of fighters, and the Free Syrian Army. And there are families of the opposition,” said Abdullah.

Abdullah, whose group performs search-and-rescue missions in the city, says space is running out for those in the area. “There’s no place for people to live. Many of the people are in sub-par housing … with no doors or windows,” he said.

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And the situation appears to be getting worse for them. In addition to food shortages, reliance on limited gas for power, and intense fighting, the medical situation remains grave.

According to Doctors Without Borders (MSF), medical supplies are running extremely low in east Aleppo, and hospitals have been severely damaged from air strikes.

First responders such as Abdullah face hardships, too. “Most ambulances are also damaged or out of service and roads are totally blocked with rubble from the destruction, making movement very difficult for first responders, and putting at risk the severely wounded who often cannot access emergency care on time,” said Evita Mouawad, an adviser for MSF in neighbouring Jordan.

Meanwhile, rebels in Aleppo continue to fight on, despite what appears to be an imminent government victory. “We cannot do anything to protect the civilians in the city. The regime has all kinds of weapons,” said Ahmad Jalal, a fighter in one of the armed groups.

“We all face the same fate. Every place in east Aleppo faces bombing and there’s no safe place at all.”