Hundreds dead in Aleppo as authorities strive to extend ceasefire

At least 253 civilians, including 49 children, have died in shelling, rocket fire and air strikes in Aleppo since the surge in fighting in Aleppo, where government forces are battling rebels for control.

Russian officials said on Sunday they were calling on the Syrian government to include Aleppo in a temporary truce already in place in Latakia and around Damascus.

US Secretary of State John Kerry called for a "countrywide" cessation of hostilities.

"We are talking directly to the Russians, even now," Kerry said, after a week in which Moscow refused to rein in its ally, Syrian President Bashar al-Assad. Russia maintained for days that it would not urge Assad's forces to stop air raids on the city as they were targeting groups not covered by February’s ceasefire.

But on Sunday, there seemed to be a change in tone after government forces dropped barrel bombs in the Hritan, Kafr Dael, Bab al-Haded and Kastelo neighbourhoods.

Most of the fighting was concentrated in the countryside in an apparent attempt to cut off rebel-held areas from supply routes on the Turkish border.

"Currently active negotiations are under way to establish a 'regime of silence' in Aleppo province," said Lieutenant-General Sergei Kurylenko to Russian news agencies.

A Syrian pro-government newspaper said on Thursday the army was preparing an offensive to recapture all of Aleppo and the surrounding province.

Hospitals have also been bombed in the process.

"Aleppo has been experiencing extreme conflict for four years now and 95 percent of the medical staff in the city has quite understandably already fled," said Doctors Without Borders representative Sam Taylor.

"There are only 70 to 80 doctors in Aleppo. That's a ridiculously small amount of medical staff trying to deal with an enormous amount of trauma injuries,” he added.