BEIRUT -- The U.S. and Russia escalated their war of words over Syria Thursday as government forces kept up their assault on Aleppo's rebel-held quarters and registered tenuous gains.

Government forces seized the Handarat neighbourhood along the contested city's northern flank, forcing rebels to withdraw further from a crucial supply route to the city's east, the Castello Road, pro-government media and observers said. A government blockade of the road has kept the opposition-run east under siege since mid-July, with the exception of a month-long period where rebels broke through the government's southern line.

But gains have proven ephemeral in the battle for Aleppo: government forces captured Handarat last Saturday, only to surrender it again Sunday.

Syria's military also released a video purporting to show a freshly captured neighbourhood in the city's historic centre.

The video shows damaged traditional buildings, with arched ceilings and stone walls, in the Farafra neighbourhood which rests at the foot of the city's towering central citadel. Soldiers and allied militants are seen walking past mounds of debris, twisted metal bars, and caved-in ceilings. The government claimed it expelled rebels from the front-line neighbourhood Tuesday.

A top Russian diplomat meanwhile called a U.S. threat to halt co-operation with Russia in the Syria conflict an "emotional breakdown" and said Russia is willing to support a 48-hour cease-fire around Aleppo.

Deputy Foreign Minister Sergei Ryabkov on Thursday rejected Washington's calls for a seven-day pause in hostilities, but said Russia is willing to support a 48-hour truce for humanitarian purposes.

Damascus blocked assistance from reaching eastern Aleppo during a week-long cease-fire earlier this month.

Airstrikes meanwhile hit the last remaining bakery serving a town north of the besieged city, putting it out of service, activists said.

The Britain-based Syrian Observatory for Human Rights said a number of airstrikes hit the town of Anadan and its bakery Thursday.

Adnan Medlej, an activist from Anadan, said the bakery was hit shortly after it distributed bread to the town's remaining 2,000 residents and others in nearby villages. After intense bombings that devastated the town's infrastructure, most residents have fled to other areas in rural Aleppo province.

A video shot by Medlej shows the bakery destroyed and a crater outside, with water leaking and walls schorched.

On Wednesday, government shelling near a bread distribution centre in Aleppo city killed six people.


Associated Press writer James Heintz in Moscow contributed to this report.