The massive Saturday bombing that killed 126 people in Aleppo Province was the result of an attack by al-Qaeda’s Nusra Front, according to a quote from President Bashar Assad cited by a Lebanese television network.
No one ever claimed responsibility for the attack, which targeted Shi’ite civilians being evacuated from Idlib Province as part of a “town swap” deal between the government and rebels. Rebels forced the Shi’ites to stop in a rebel-held district for hours instead of delivering them to Aleppo city, citing a disagreement over the transfers with the Syrian government, when a suicide bomb targeted the convoy.
The circumstances of the attack, targeting both Shi’ite civilians and moderate rebels, wouldn’t certainly fit with a Nusra attack, though again there has been no claim of responsibility making it difficult to confirm who did it.
Thousands of people on both sides have been relocated in the town swap evacuations, and the first round reportedly finished earlier today. It is not totally clear how quickly further evacuations will happen, though other than the Saturday bombing and the delays by the rebels, things went relatively smoothly.