The children aged between 8 and 12 years. The local rescuers recovered 40 bodies from the wreckage in Chittagong district, 216 kilometers (136 miles) southeast of the capital, Dhaka.
According to the police official Iftekhar Hasan, it feared that the death toll might rise as more bodies are supposed to be trapped inside the sunken vehicle.
"According to several witnesses the boys were singing and dancing on board the truck," said the official. "The truck skidded off the muddy road and turned (over) as it plunged into the canal."
Hundreds of people, including the children's parents and guardians gathered at the spot to look for their loved ones.