The current chair of the task force on humanitarian access in Syria, Jan Egeland, on Thursday said that food and medical equipment for as many as 150,000 people stood ready in the western part of the city, if safe passage could be guaranteed.

"The Russian Federation announced that ... they want to sit down in Aleppo with our people there to discuss how we can use the four corridors to evacuate people out," Egeland told reporters in Geneva. He said that Russia had pledged to respect the corridors and that "we [the UN] now feel confident that the armed opposition groups will do the same."

Such corridors had been opened in the past, but few people made use of them. In the mean time, however, the Syrian government - with Russian backing - has stepped up its offensive and reclaimed some territory from rebel hands in the divided city.

UN special envoy Staffan de Mistura said on Thursday that about 30,000 people were receiving aid after fleeing the east of Aleppo - taking the number of displaced in Aleppo to 400,000.

The UN had previously appealed for a ceasefire to allow aid workers to assist civilians, a request rejected by Russia and Syria. Moscow's proposed solution on Thursday was to open the humanitarian corridors instead.

"A humanitarian corridor can work if all the armed actors respect it," Egeland said, warning that civilians were also at risk of attack from opposition fighters when trying to leave the rebels' territory.

Rebels reportedly reclaim some territory

Thousands of civilians are pouring out of eastern Aleppo as government forces advance. Rescuers say dozens have been killed while trying to flee rebel-held areas, with hundreds reportedly seeking refuge in government-controlled areas being detained.

Syrian opposition fighters have reversed recent gains by regime forces in a strategic area in the divided city of Aleppo, the Syrian Observatory for Human Rights reported on Thursday. The rebels wrested back half of the Sheikh Said district in the southern part of eastern Aleppo following a counter-attack they launched against regime troops and their allies, it said.

"Sheikh Said is crucial for the opposition factions because, if they lose it, the regime would tighten the noose on areas deep inside eastern Aleppo," Observatory head Rami Abdel-Rahman told the German news agency dpa.

On Wednesday, the Syrian government had reported that its forces had taken full control of Sheikh Said neighborhood.

Since its outbreak, the Syrian civil war has claimed an estimated 400,000 lives and displaced millions.

jbh/msh (dpa, AFP)