A young girl who survived an attack on a bus convoy evacuating civilians from a besieged Syrian town has been filmed smiling at the camera in powerful footage being shared online.

The child, swathed in bandages, was injured at the weekend when a suicide bomber detonated explosives onboard a crowded vehicle.

He killed at least 126 people, including 88 children.

The bus passengers were refugees, escaping the towns of Kefraya and al Foua, which are held by forces loyal to the Syrian president, Bashar al-Assad, but have been under siege from rebel forces for more than two years.

The attack was reportedly carried out by a man who enticed children waiting near the buses at a checkpoint to come closer to his vehicle by handing out crisps and sweets, several rebel and regime media sources said.

Scores were injured by shrapnel, including the girl in the video, who was filmed in the back of an ambulance being treated for a head injury.

In the footage, first broadcast by the official Syrian Arab News Agency, a large plaster covers a cut on her cheek and her beige top is covered in blood.

Initially she looks upset and frightened but then she breaks into a smile as someone tries to amuse her by inflating two surgical gloves.

Aleppo before the Syrian Civil War Show all 12 1 /12 Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A man crosses a street in Aleppo, December 12, 2009 Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A vendor sits inside an antique shop in al-Jdeideh neighbourhood, in the Old City of Aleppo, December 12, 2009 Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A view shows part of Aleppo's historic citadel, overlooking Aleppo city, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A view shows part of Aleppo's historic citadel, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War Visitors walk inside Aleppo's Umayyad mosque, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War People walk inside the Khan al-Shounah market, in the Old City of Aleppo, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A man walks past shops in al-Jdeideh neighbourhood, in the Old City of Aleppo, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War People walk along an alley in al-Jdeideh neighbourhood, in the Old City of Aleppo, Syria Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War Visitors tour Aleppo's historic citadel, Syria December 11, 2009 Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A general view shows the Old City of Aleppo as seen from Aleppo's historic citadel, Syria December 11, 2009 Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War People walk near Aleppo's Bab al-Faraj Clock Tower, Syria October 6, 2010 Reuters Aleppo before the Syrian Civil War Aleppo before the Syrian Civil War A man stands inside Aleppo's historic citadel, overlooking Aleppo city, Syria December 11, 2009 Reuters

The explosion occurred as the buses passed through Rashidin in rebel territory, near to the town of Aleppo.

Qatar and Iran brokered the evacuation deal, which also allows residents of opposition towns Madaya and Zabadani to cross safely to rebel-controlled Idlib province.

The bombing has not been claimed. While both sides have blamed the other for the attack, it is likely to have been carried out by extremist factions of Jaish al-Fatah, a rebel umbrella group with al Qaeda links, which was reportedly unhappy that the regime was allegedly bussing out more fighters than agreed.

By midweek the full evacuation programme appeared to have restarted after stopping briefly, both rebel and state media said, with 3,000 more residents of the pro-government towns al Foua and Kefraya leaving on 45 buses.

Another 11 buses carrying some 500 people, including opposition fighters, left Madaya and Zabadani, near Damascus, heading toward northern rebel-held Idlib province.

The multiple-stage transfer deal, which could see 30,000 in total moved across front lines, has been widely criticised as not meeting base-level safety standards.