Tens of thousands flee Aleppo assault by Syrian government

Tens of thousands of people are reported to have fled Aleppo as the Syrian government and its Russian allies press an offensive on rebel forces that led to the breakdown of UN-brokered peace talks.

The Syrian Observatory for Human Rights said the exodus began on Monday as government forces mounted attacks that by Thursday had severed the main rebel supply route into Aleppo city and broke opposition sieges on the towns of Nubol and Zahraa.

It said 40,000 people had fled the fighting, and counted more than 500 air raids this week in Aleppo province alone. The observatory reported that Russian bombing on Thursday had killed at least 21 civilians in Aleppo city.

The UK-based SOHR said many people had fled to Azaz, a town on the Turkish border, and the Kurdish town of Afrin, which has become overloaded with refugees.

Mercy Corps, an international aid group, said on Thursday that it had been forced to suspend food deliveries to several villages due to the number of Russian air attacks. 

A spokesman told the AP news agency that about 21,000 Syrians who have fled the fighting recently arrived at the nearby Turkish border.

Turkey's Prime Minister Ahmet Davutoglu separately said 10,000 Syrians were waiting at the border to enter Turkey and that up to 70,000 others who had been sheltering in camps north of Aleppo were moving towards his country. 

A Syrian army source told the Reuters news agency that it expected to complete the encirclement of Aleppo city within days.

"If the army completes its operation in the northwest direction from Zirba, and in the southwest direction from Nubol and Zahraa, all the supply routes will be cut. And this is soon," the source said. Zirba lies southwest of Aleppo.

The mass displacement and ongoing fighting threatens to create a new humanitarian disaster as world leaders and diplomats gathered in London to discuss a renewed aid push for Syria.

The UN wants pledges of $9bn this year alone to aid the millions of Syrians who have fled their homes in almost five years of fighting. The US, UK and Norway promised to donate a combined total of about $4bn, but much of that money will be spread over the next four years.

The Syrian army advances on Aleppo have been boosted by the Russian bombing and the involvement of the Lebanese group Hezbollah.

Hezbollah on Thursday published videos of its troops celebrating with residents in Nubol and Zahraa after breaking the rebel siege.

Activists inside Aleppo city on Wednesday said the government had dropped leaflets warning residents they faced "bloodshed" and the "death of loved ones" if they did not expel opposition forces from their areas.

On the same day in Geneva, the UN envoy to Syria, Staffan de Mistura, suspended much-vaunted peace talks after both sides refused to meet each others' demands.

The opposition High Negotiating Committee said it needed an end to bombing and sieges on rebel-held areas before any talks could take place. The Syrian government refused the requests as "preconditions", and Russia said it saw no reason to stop its bombing campaign against "terrorists".