Syrian army reaches main road into rebel-held Aleppo-rebels

"It's completely cut," Zakaria Malahifji of the Aleppo-based rebel group Fastaqim, told Reuters.

A second source from an Aleppo-based rebel group, the Levant Front, confirmed that the pro-government forces had reached the highway, known as the Castello Road. Both said fighting continued as rebels tried to take back lost ground.

Aleppo has been a major battleground in the Syrian conflict, now in its sixth year.

Forces loyal to President Bashar al-Assad's government had already captured ground overlooking Castello Road nearly two weeks ago, effectively shutting it down-although a local opposition figure said a few supplies had still been getting through to the roughly 300,000 people in rebel-held districts.

Commander Abu Ibrahim, from the Nuri Al Din Zinki rebel group, said the regional rebel command centre was now telling people to stay away from the area.

"The Castello Road is completely cut as a result of the clashes and the advance of the Assad gangs. We warn all civilians from using the road at all by any means," he said.