In what may serve as a catalyst for another US military intervention in Syria, a blast has reportedly hit a convoy of buses carrying evacuees from the government-held towns of Fuaa and Kefraya near the Syrian city of Aleppo. The blast was reportedly caused by a suicide attacker detonating a car bomb according to Syrian state TV while local press estimates that up to 60 civilians have been killed in the explosion.

.@SARC_Aleppo Special source to #A24: "Initial estimate 60 civilians from Kafraya and Foa killed in the explosion" — Aleppo24 (@24Aleppo) April 15, 2017

A photo carried by local media showed a number of bodies strewn on the floor with a huge plume of black smoke rising in the background.



A graphic video of the aftermath of the explosion by what reportedly was an anti-Assad suicide bomber: viewer discretion.

VIDEO (GRAPHIC): Aftermath of the bombing which targeted civilian evacuees from Fuaa & Kefraya, #Syria - @Dalatrmpic.twitter.com/Zzwhbrz2Xy — Conflict News (@Conflicts) April 15, 2017

According to AP, The buses carrying nearly 5,000 pro-government evacuees have been stuck in an area on the edge of Aleppo city, as a much criticized population transfer deal stalls. According to the deal, more than 2,000 residents, activists and gunmen from areas besieged by government forces were also evacuated. But as the government and rebels disagreed over the number of gunmen to be evacuated, the buses were left stuck at two separate parts, but adjacent parts of the city.

BBC adds that rebels say Damascus breached the terms of the deal brokered by Iran and Qatar.

They accuse the government of trying to bring out more loyalist fighters from the north-western towns of Foah and Kefraya than agreed. A previous attempt at mutual evacuations failed in December when rebels burnt coaches due to be sent to the towns.

Last month, the UN described the situation there, and in the rebel-held towns of Madaya and Zabadani, near Damascus, as "catastrophic", with more than 64,000 civilians "trapped in a cycle of daily violence and deprivation".

According to an AFP correspondent at a collection point in rebel-held territory at Rashidin, west of Aleppo speaking before the reports of an explosion, said buses carrying government evacuees had not moved in 30 hours. The Syrian Arab Red Crescent was distributing food and water to the waiting passengers, who include 3,700 civilians, the agency adds. Many people are reported to have died as a result of shortages of food or medicine in the four towns.

Foah and Kefraya, most of whose residents are Shia Muslims, have been encircled by rebels and al-Qaeda-linked Sunni Muslim jihadists since March 2015. Madaya and Zabadani, which are predominantly Sunni, have been besieged since June 2015 by the Syrian army and fighters from Lebanon's Shia Muslim Hezbollah movement.