Syria’s government says it has opened a new humanitarian corridor for those who wish to leave east Aleppo during the city’s temporary ceasefire, but residents inside the siege barricades say they are being prevented from leaving by rebels.

Friday was the second day of a three-day ceasefire during daylight hours announced by the Russian and Syrian governments in a bombing campaign which has killed approximately 500 people in the last month.

Russia announced that the pause would allow medical evacuations, and let both civilians and rebels leave for neighbouring rebel-held Idlib province under a promised amnesty.

The rebel coalition Free Syrian Army put out a statement rejecting the deal. Nonetheless, thousands of leaflets dropped on east Aleppo by helicopters urged the 250,000 strong population to leave the rebel neighbourhood - and promised fighters death if they did not lay down their arms.

At least two major corridors and six more safe exits were set up by Syrian troops, while state television broadcast footage of green buses waiting on the government-held side of the city - but only a “small number” were evacuated on Thursday, state media said.

Several residents inside east Aleppo reported that people trying to cross into the West were shot at by mortar fire. ITV news crews reporting from West Aleppo said they saw rebel mortar rockets targeting checkpoints “scatter people as they fled for their lives”.

Rebel sources and activists from the Aleppo Media Centre said reports of the opposition stopping evacuations were fabricated.

Video shows amazing rescue of child as shelling resumes in Aleppo

The UN did not say assign blame, but the agency’s humanitarian wing said that plans to evacuate people in need of medical attention had broken down on Friday, citing a “lack of security assurances” from both sides. “The necessary conditions were not in place to ensure safe, secure and voluntary movement of people,” spokesperson Jens Laerke said in Geneva.

Syria's ambassador to the UN in Geneva accused the international body of “quoting the demands of terrorists inside Aleppo to justify their failure to evacuate.“

“The evacuation of wounded should be done unconditionally,” Hussam Aala added.

The UN has asked for the ceasefire to be extended. East Aleppo - under siege by regime forces since July - is running critically low of medical supplies, fuel and food.

A week in Aleppo - witnessing the fierce battle for Syria's largest city Show all 6 1 /6 A week in Aleppo - witnessing the fierce battle for Syria's largest city A week in Aleppo - witnessing the fierce battle for Syria's largest city aleppo-woman.jpg A woman walks through rubble from a building destroyed by shelling from forces loyal to Syrian President Bashar Al-Assad in downtown Aleppo REUTERS/Goran Tomasevic A week in Aleppo - witnessing the fierce battle for Syria's largest city aleppo-gun.jpg A Free Syrian Army fighter gestures during a fight with forces loyal to Syrian President Bashar Al-Assad in downtown Aleppo REUTERS/Goran Tomasevic A week in Aleppo - witnessing the fierce battle for Syria's largest city aleppo-truck.jpg Members of the Free Syrian Army ride on pick-up trucks in Aleppo's district of Salheddine REUTERS/Abdel Razzak al-Halabi A week in Aleppo - witnessing the fierce battle for Syria's largest city aleppo-body.jpg The body of a civilian, whom activists say was killed by forces loyal to Syria's President Bashar al-Assad, is seen in front of the wreckage of a bus in Aleppo's district of Salheddine REUTERS/Abdel Razzak al-Halabi A week in Aleppo - witnessing the fierce battle for Syria's largest city aleppo-wounded.jpg A Free Syrian Army fighter is wounded during a fight with forces loyal to Syrian President Bashar Al-Assad in downtown Aleppo REUTERS/Goran Tomasevic A week in Aleppo - witnessing the fierce battle for Syria's largest city ALEPPO-WRECKAGE.jpg A man carries belongings from his shop destroyed by shelling from forces loyal to Syrian President Bashar Al-Assad in downtown Aleppo REUTERS/Goran Tomasevic

Inside the siege barricades, protesters gathered in the neighbourhood of Shaar on Thursday night with banners reading ‘Revolutionaries don’t give up’, ‘No to displacement’, and ‘No to Putin’ to demand a permanent end to the shelling, rather than just a ceasefire.

Similar reports emerged during last month’s US- and Russian-brokered ceasefire, when UN aid was prevented from reaching civilians inside the siege barricades both by the Syrian government, who claimed the trucks did not have permission permits from Damascus, and by protesters who gathered to block roads, demanding the siege be lifted.

Analysts expect the Syrian operation to retake the entire city to intensify after the current truce ends. The intense bombing campaign - followed up by a slow but steady ground troop assault - to retake the city would mark a significant victory for President Bashar al-Assad, ending rebel control of Syria’s major urban centres.