Syria Rebels Call for Truce as Aleppo Losses Mount

Rebels in Aleppo called for a five-day truce and the evacuation of civilians Wednesday after losing more territory including the Old City to a Syrian army offensive.

Heavy fighting in the city stoked mounting international concern, with six Western powers urging a ceasefire and U.N. chief Ban Ki-moon describing the plight of civilians as "heartbreaking."

U.S. Secretary of State John Kerry was to hold fresh talks with Russian counterpart Sergei Lavrov in Hamburg, Germany, later Wednesday on efforts to halt the fighting.

A blistering new offensive launched last month has seen President Bashar Assad's forces move closer than ever to retaking all of Aleppo and winning their most important victory yet in the civil war that began in 2011.

Rebel fighters, who took control of east Aleppo in 2012, have suffered a string of defeats in recent days, losing about 80 percent of their former territory in the city, according to the Syrian Observatory for Human Rights.

Regime forces scored another important victory on Wednesday when the rebels retreated from the Old City, the historic heart of Aleppo, said the Observatory, a Britain-based monitor.

Increasingly cornered in a sliver of territory in the city's southeast, rebel factions issued a joint statement calling for an "immediate five-day humanitarian ceasefire."

The statement also called for "the evacuation of civilians who wish to leave" the city's east to rebel territory in northern Aleppo province. 

- Disaster 'before our very eyes' -

Opposition fighters have rejected talk of leaving Aleppo, however, and Syria's government has said it will not agree to any ceasefire without a full rebel withdrawal.

The army extended its advances on Wednesday afternoon, with state media saying government troops had taken control of the Bab al-Nayrab, Al-Maadi and Salhin neighborhoods.

Remaining rebel-held districts were coming under heavy bombardment, an AFP correspondent in the area said. 

The statement from the six Western powers -- Britain, Canada, France, Germany, Italy and the United States -- said a humanitarian disaster was "taking place before our very eyes" in Aleppo.

"The urgent need now is for an immediate ceasefire to allow the United Nations to get humanitarian assistance to people in eastern Aleppo," the statement said.

It lashed out at the regime in Damascus and its "foreign backers, especially Russia," accusing them of blocking emergency help.

Moscow is a key Assad ally and launched an air war in support of his forces last year, while Washington and other Western nations have supported rebel forces.

U.N. chief Ban also appealed for a ceasefire, saying in Vienna: "What we have seen most recently in eastern Aleppo, that is really heartbreaking."

Moscow and Washington have traded blame this week over a series of stalled efforts to bring about a ceasefire.

The assault has prompted a mass exodus of east Aleppo residents and the Observatory said Wednesday that at least 80,000 had now fled their homes.

It said the figure included residents who had sought refuge in the government-held west of the city and a Kurdish-controlled enclave, but not those who fled to remaining rebel territory.

- Fleeing civilians -

Assad's government has been urging civilians to leave east Aleppo for months and accused rebels of holding residents hostage for use as "human shields."

Overnight, Syrian soldiers helped residents evacuate newly recaptured areas near the Old City.

Inside one bus, evacuees could be seen huddling together, a baby wrapped in heavy blankets fast asleep at his mother's feet as she sat waiting for the vehicle to leave.

"The situation was very difficult," said Um Abdu, 30, as she left the Bab al-Hadid neighborhood with her husband, five children, mother and siblings. 

"We lived on edge for the last four days," she told AFP. "The gunmen were using us to protect themselves... but then the army came and we were able to leave."

The government offensive has killed at least 369 people in east Aleppo, including 45 children, the Observatory says.

Rebel fire into the west of the city has killed at least 92 people, including 34 children, in the same period, it says.

Aleppo city's surgeon general Fawwaz Hajjo told AFP that seven children were among 12 more people killed Wednesday in rebel rocket attacks.

Russia said Wednesday that an army colonel working as a military adviser in Syria had died several days after being wounded by rebel shelling in Aleppo.

More than 300,000 people have been killed since the conflict began, and over half the population has been displaced, with millions becoming refugees.