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 centre. 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 neighbourhood 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.  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.  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.  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 UN said last week. The Syrian Observatory for Human Rights monitoring group says that number is likely in the tens of thousands.
As the humanitarian crisis in besieged Aleppo worsens rebels have called for a truce from Syrian bombardment, but the call has been largely rebuffed.