ALEPPO, Syria/BEIRUT: The evacuation of people from eastern Aleppo was suspended Friday and a Reuters witness heard at least four blasts at a location where buses had been departing.

A state-run Syrian TV station reported that rebels had breached an agreement with the government by trying to take prisoners with them during the evacuation.

A Syrian official overseeing the evacuation told Reuters it had been obstructed due to "obstructions."

Evacuations of rebel fighters and civilians including wounded from the last opposition-held areas of Syria's Aleppo had been gathering pace earlier Friday under a cease-fire that would see the government retake the city, activists and a rebel official said.

At least 6,000 people had left rebel-held Aleppo in several convoys of buses and ambulances since Thursday, when the evacuations began, Zakaria Malahifji, a Turkey-based official in the Fastaqim rebel group told Reuters.

The number included some 900 wounded, both fighters and civilians, he said.

The Birtain-based, opposition-aligned Syrian Observatory for Human Rights group said the total number was closer to 8,000, including some 3,000 fighters and more than 300 wounded.

A statement from the pro-Damascus military alliance that includes Hezbollah said more than 8,000 had left in 10 convoys.

The number of buses being used had doubled to about 50, Malahifji said, suggesting the speed of evacuations was increasing.

"There are a lot of buses now," Observatory director Rami Abdul-Rahman said.

Aleppo had been divided between government and rebel areas of control in the nearly six-year civil war, but a lightning advance by the Syrian army and its allies that began in mid-November saw the insurgents lose most of their territory in a matter of weeks.

The cease-fire deal, brokered by Damascus ally Moscow and rebel backers Turkey earlier in the week, initially broke down Wednesday as fighting resumed and Iran reportedly introduced a new demand for the evacuation of two Shiite-majority villages in Idlib.

Thousands were expected to evacuate the villages, Foua and Kefraya, which have long been besieged by insurgents in the mostly rebel-held province. It was unclear why the evacuations had not yet begun, but a convoy set off to evacuate the villages Thursday, Syrian state media said.