ABC
Hospitals will soon start running out of fuel in the Syrian city of Aleppo and food supplies may only last one month if humanitarian supplies are not permitted to enter the newly besieged eastern half of the city, the United Nations has said.
Russian and Syrian regime airstrikes reportedly killed 28 people in Aleppo on the weekend, including five children and seven women.
Video purportedly filmed after an attack on the rebel-controlled neighbourhood of Al-Maysar shows people carrying lifeless bodies from the rubble, while a teenage boy covered in blood shouts repeatedly for his mum.
They are trapped — under constant fire from Syrian and Russian warplanes above and now surrounded on all sides by Assad regime forces.
Syrian Government forces seized control of the only road going into rebel-held eastern Aleppo on Sunday, leaving no way for people or supplies to get in or out of the opposition-controlled area.
"They are only a few hundred meters away, they are having fun, waiting for any civilians to pass," 27-year-old human rights activist Muhammad Zain said.
He, like hundreds of thousands of people, is now stuck inside the besieged city.
"Slow death this is what we have here. I can't tell you how much we are concerned and worried, we fear death," he told the ABC over a bad internet connection from eastern Aleppo.
"They are waiting for this moment to punish the people collectively, even punishing people who are not supporting the rebels, nor the regime.
"Any civilian could be a target."
The acting UN Humanitarian Coordinator for Syria, Jakob Kern, told the ABC the UN was extremely concerned about the approximately 300,000 people trapped in rebel-held Aleppo.
"The Castello Road was the last access road into east Aleppo city. Now it's cut off completely humanitarian commodities have been unable to get in or out," Mr Kern said over video call from Damascus.
"We are extremely concerned because of the large number of people — it is 200,000 to 300,000 people, it is a very high number."
'Aleppo is another scale entirely'
Mr Kern said hospitals would soon run out of fuel and be unable to operate. The UN believes there is only enough food in Aleppo to feed 145,000 people for one month.
"We will be concerned in very short time when these supplies are running out," Mr Kern said.
When speaking of Aleppo Mr Kern evoked the situation in Madaya, the rebel-held town near Damascus where children starved to death.
"Potentially we will see the same as in Madaya and in other besieged areas that there will be people rationing of supplies will happen and people will get less and less food. And will get less and less access to medical supplies," he said.
Who is fighting who in Syria ?
For more than five years, the Syrian people have suffered a catastrophic series of wars that have killed or injured hundreds of thousands of people and displaced millions.
Many observers see the encirclement of Aleppo as a landmark moment in this five-year-long civil war.
"Really Aleppo is just another scale entirely," said James Sadri, the director of The Syria Campaign in Beirut, an advocacy group that calls for humanitarian action in the war-ravaged country.
"Aleppo has long been a key centre of political opposition to the regime in Damascus. Even before the uprising really. So what happens here is absolutely critical."
Mr Sadri said it was unjustifiable that the world had failed to act to help protect civilians in Aleppo.
"You know we have got four of the five permanent security members that are now flying in Syrian airspace and yet none of them is doing anything to stop this aerial war on these civilians which is now focused on Aleppo," Mr Sadri said.
He said it was crucial the UN took a stronger stance towards the Assad regime.
"We need a bold United Nations that can stand up. And it needs to call very clearly out this government siege on Aleppo and make it stop," he said.
"The UN needs to find its independent voice and really start putting a foot down."