Five persons were killed in a powerful blast in the curfew-bound Nagtoli area of west Nepal's Achham district.

Among those killed in Wednesday night's blast were an assistant health worker and the chairman of the management committee of a local school, local police sources said.

However, the government claimed that the victims were Maoists killed in an accidental explosion while trying to plant a bomb in the area.

The local administration has imposed night curfew in Mangalsen, the district headquarters of Accham, for the past one and a half month for security reasons.