The five bodies have been fished out and divers have been pressed into service to find out the remaining five children, a police officer said.
The 13 children, residents of Kumhar Sang village, had gone boating for recreation when the mishap occurred, he said, adding three children swam to safety.
The deceased have been identified as Rupam Kumari (8), Abhishek Kumar (10), Jhitni Kumari (12), Chhotki Kumari (8) and Sachin Kumar (10), the officer said.