Mortally wounded civilian casualties are being zipped into body bags while still alive as the bombardment of Aleppo overwhelms the city's handful of remaining doctors, says the head of a Syrian relief organisation.
Syrian forces supported by Iranian-backed militias and Russian air power began their push to take the whole of the divided city after a ceasefire collapsed last month.
Dr Zaidoun al-Zoabi, head of the Union of Syrian Medical Relief Organisations told Morning Report these were the "worst days".
"Full seige, shortage of fuel, no electricity, no water. Hospitals are destroyed one after another."
Fewer than 30 doctors were still working in six hospitals for a population of 275,000, he said.
"Each doctor has to see 100 wounded persons a day - this means they don't sleep, they don't take rest. There is a huge shortage of medical supplies. Many people are just declared dead before really dying simply because their doctor has to decide who has more chances to live and then he treats the one who has higher chances to live. The one who doesn't is simply put into a bag, waiting for his death.
"The doctors are traumatised, angry and exhausted," he said, and he held no hope for the city. "We are without hope, finish ... We feel that this is the end of the world."
Rebel-held areas were subject to dozens of air strikes overnight, allowing government troops to gain ground in the north of the city. The Syrian army told insurgents to leave their positions, offering safe passage and aid supplies.
While Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry spoke by phone to discuss normalisation of the situation, Britain said the bombing of hospitals by forces loyal to Syrian President Bashar al Assad made it impossible talk about peace.
"It is the continuing savagery of the Assad regime against the people of Aleppo and the complicity of the Russians in committing what are patently war crimes - bombing hospitals, when they know they are hospitals and nothing but hospitals - that is making it impossible for peace negotiations to resume," British Foreign Secretary Boris Johnson said.
An air campaign by the Syrian government and its allies has been reinforced by a ground offensive against the besieged eastern half of Aleppo, where insurgents have been holding out.
The Syrian Observatory for Human Rights and the Syrian military said on Sunday that the army and its allies had advanced south from the Handarat refugee camp north of the city, taking the Kindi hospital and parts of the Shuqaif industrial area.
Zakaria Malahifji, of the Aleppo-based rebel group Fastaqim, told Reuters there were clashes in this area on Sunday.
The Observatory said air strikes and shelling continued on Sunday and there was fierce fighting all along the front line which cuts the city in two.
The Syrian army said that rebel fighters should vacate east Aleppo in return for safe passage and aid supplies.
"The army high command calls on all armed fighters in the eastern neighborhood of Aleppo to leave these neighborhoods and let civilian residents live their normal lives," a statement carried by state news agency SANA said.
'The situation in Aleppo is beyond dire'
East Aleppo came under siege in early July after its main supply route, the Castello Road, fell under government control.
International attempts to establish ceasefires to allow in United Nations humanitarian aid have failed, although other aid groups have brought in limited supplies.
The relentless Russian and Syrian air campaign has badly damaged hospitals and water supplies.
The UN's Under-Secretary-General for Humanitarian Affairs, Stephen O'Brien, said he was "deeply alarmed by the ferocious pummeling of eastern Aleppo" and reiterated UN calls for a pause in fighting, medical evacuations and access for aid.
"The health system is on the verge of total collapse with patients being turned away and no medicines available to treat even the most common ailments."
"With clean water and food in very short supply, the number of people requiring urgent medical evacuations is likely to rise dramatically in the coming days," he said.
On Saturday, the largest trauma and intensive care center in eastern Aleppo was badly damaged by air strikes and had to close. Two patients were killed.
The Syrian American Medical Society (SAMS), which partly supported the hospital, said the hospital had been hit seven times since July, with three attacks this week alone.
"The situation in Aleppo is beyond dire ... People are stuck under the rubble and we can't get to them because of the intensity of the shelling. We are pleading for help to stop the bombing," said Mohamed Abu Rajab, a SAMS nurse at the hospital.
SAMS said only five hospitals remained operational in east Aleppo.
The Syrian Foreign Ministry said in a statement carried by state media that the participation of Russia's air force in the conflict now in its sixth year had "tightened the noose on terrorist groups and reduced their ability to spread terror to other countries".
The Syrian government refers to all groups fighting against it as terrorists.
- RNZ / Reuters