Civilians in Aleppo Remain Trapped After Evacuation Suspended

— LONDON -- The evacuation of civilians and fighters from the last rebel-held enclave of east Aleppo in Syria stopped on Friday, a day after ambulances and buses drove thousands of residents out of the area.

Residents including children who had been waiting to leave had to return to their homes after the operation was suspended on Friday, according to the World Health Organization.

"The worrying part of this is there are still in besieged enclaves of Aleppo high numbers of women and infants, children under 5, that need to get out," Elizabeth Hoff, WHO representative in Syria, told a news briefing in Geneva, speaking from west Aleppo. "Now with the operation aborted, they have gone back to their houses."

She said that WHO, the International Committee of the Red Cross and the Syrian Arab Red Crescent were told to leave the area and that no reason was given.

Robert Mardini, the Middle East director for the International Committee of the Red Cross, confirmed the suspension but also didn’t give a reason.

Syrian state TV accused rebels of firing on a convoy of evacuees at a checkpoint while anti-government activists said that pro-government militias had blocked the passage to protest the siege of two Shiite villages, Foua and Kafraya, by rebels, the majority of whom are drawn from the country’s larger Sunni population.

“The reason for the stop of the operation is pressuring the rebels,” Zakaria Amino, the deputy head of east Aleppo's local council, told ABC News. He also blamed Tehran, a Shia ally of Syrian President Bashar al-Assad, for a hand in halting Aleppo’s evacuations. “Iranians are using this to pressure rebels to allow wounded and injured to leave Foua and Kafraya.”

Hassan Dahhan, a lawyer, who left besieged east Aleppo for the countryside on Friday morning, said that the Syrian government allowed some residents to leave in their own cars because there weren’t buses to drive them out of the area.

“I left in my car and I had a wounded person with me in need of treatment,” he told ABC News. “We spent the night outside in the cold. The situation is miserable. Women and children spent the night outside and the temperature is below freezing.”

The Syrian Observatory for Human Rights, a U.K.-based monitoring group, said that 8,500 people, including around 3,000 rebels and 360 wounded, have left the rebel-held areas of east Aleppo in buses and ambulances.

On Thursday, the head of the ICRC in Syria, Marianne Gasser, said that the evacuation could take days.

"When we arrived, the scene was heartbreaking,” Gasser said in a statement. “People are faced with impossible choices. You see their eyes filled with sadness. It was very moving.”

She said that no one knows how many people are left in the last rebel-held areas of Aleppo. The U.N. envoy to Syria, Staffan de Mistura, estimated on Thursday that 50,000 people, including 40,000 civilians, remain trapped there.

Before the war, Aleppo was Syria’s largest city with a population of 2 million. The city had been divided into the rebel-held east and the government-held west since 2012. In recent months, the Syrian government, with help from Russia, Iran and other allies, intensified its airstrikes on eastern Aleppo and tightened the siege in an attempt to gain full control of the area, rebel-held until recently. Gaining control of the eastern neighborhoods is a strategic victory for Assad