While five boys lost their lives in the pond, another died on way to the hospital, Superintendent of Police Pankaj Sinha said.
A search is on for one boy who has gone missing, the SP added.
The accident occurred when the victims, aged between 10 and 15 years, were engaged in creating a ghat for Chhath festival. Three of them went up to the middle of the pond and drowned. When others tried saving them they met with the same fate, the police said.