BEIRUT ― Years of siege conditions mean the citizens living in rebel-held parts of Aleppo are accustomed to danger, fear and tragedy. But as the Syrian army close in on the ruined streets of the Old City, they face some unbearable choices.

“I feel this is the end,” Reem, a mother of two children, said via patchy internet connection from a rebel held district of the historic city center. Cold and a lack of water had made her children ill and the family was surviving on one meal a day.

“We’ve long accepted that if we die we die, from barrel bombs and so on, but now we’re scared that the army will come in and take my husband.”

The options facing Reem and others caught up in the rapid government advance are bleak: men of fighting age could be arrested whether they stay put or head to government-held districts. If they flee to rapidly-shrinking rebel-held areas they may only be putting that prospect off.

Whatever they do, the risk of being killed increases daily.

“We want to get out, but to Idlib or Jarablus,” Abu Youssef, 34, and from the same neighborhood said, listing two rural areas still in rebel hands.

“But there’s no way out, and the bombardment is unbearable ... We’re very scared - we heard that yesterday the regime arrested every youth they found” in areas the army recaptured, Abu Youssef said.

A neighbor who tried to leave for a government-held area a week ago had not been heard from since, he said.

A Syrian military source has denied any arrests but said the identities of people leaving rebel-held areas were being checked and that anyone who was unknown was being put into “specific places” in areas where civilians were gathered.

BOMBED IN THE STREETS

Government forces, on the front foot in the nearly six-year-old war that has killed hundreds of thousands and made more than 11 million homeless, swept into the Old City on Wednesday, saying they would not consider a ceasefire until insurgents withdraw.

Residents of the quarter, where the rubble from historic buildings fills the narrow streets, described civilians being bombed in the open and severe food and power shortages.

Damascus and Russia, which supports Syrian President Bashar al-Assad, have called on rebels to withdraw from Aleppo, disarm and accept safe passage out, a procedure carried out in other areas where rebels abandoned besieged territory in recent months.

Rebels called for a truce and civilian evacuations, but to areas of opposition control such as the northern Aleppo countryside, amid fears the government would immediately arrest men crossing from rebel-held territory.

Many people have streamed from areas rebels have left and are crammed into abandoned homes while air raids and shellfire fall around them, hoping to escape before Aleppo is retaken.

“We’ve had to move three times in a week,” said Abu Mahmoud, a 25-year-old driver, who fled with his wife and two children through areas of the Old City as they fell to government forces.

They now live in an abandoned home in one of the remaining rebel-held districts southwest of the ancient citadel. “The bombing was intense - mortar shells, rockets, phosphorus,” he said.

Residents say up to 20,000 people have fled their homes in recent days for other opposition areas. Around 18,000 had fled to government-held areas, the U.N. said last week. The Syrian Observatory for Human Rights monitoring group said that number was likely in the tens of thousands.

CONSTANT BOMBARDMENT

Bombs continue to fall even as people flee, another resident said, saying many people had been killed trying to escape Bab al-Hadid near the citadel.

“There’s been tragedy here for a long time but I’ve never seen this kind of pressure. You can’t rest for five minutes, the bombardment is constant,” he said, declining to be named.

He had sheltered for three days in the same neighborhood as Abu Mahmoud, using the building’s basement as cover during air raids. “A single mortar shell here will kill 20 people because it’s so crowded now,” he said.

Several hundred people have been killed in Syrian and Russian bombardments of rebel areas, including hospitals, in recent weeks, and in insurgent shelling of government areas, according to the Observatory.

Many people were unable to go out in search of food because of the intensity of the bombardments.

“Bread is sometimes distributed (by local authorities),” Abu Youssef said. “You can’t go out yourself to get it because the bombing is so so heavy.”

Meanwhile, communication with the outside world was becoming increasingly difficult.

“I have to turn my mobile off now because there’s no battery left ... there’s a small generator a couple of houses away where we go to charge our phones, I’ll try to get there” he said, as a loud gunshot rang out.