At least 16 people died after a car bomb detonated near a bus convoy of Syrian evacuees near the city of Aleppo on Saturday.
The convoy was believed to have been carrying evacuees from the two mostly Shia villages of Kefraya and Foah
Local media is reporting the blast was caused by a suicide attacker.
Some local reports said up to 22 people were killed in the blast and 50 were injured.
The Syrian regime and rebel groups began busing some 30,000 people out of four besieged towns on Thursday. Some 8,000 people were being bused out of Foah and Kefraya, while about 3,400 people living in two rebel-held towns near Damascus, Madaya and Zabadani, were also assured safe passage.
By Amy R. Connolly