According to reports, blast took place when cops were trying to defuse the IED that was recovered late night.
A police official said two Central Reserve Police Force (CRPF) personnel were killed and five CRPF troopers and four Bihar policemen were injured when the Improvised Explosive Device (IED) went off.
63 country - made bombs and five kilograms of explosives were seized during a raid in Bhagalpur late last night.
Bhagalpur SSP Rajesh Kumar said that the police raid, a part of the security drive conducted before the polls, was conducted following a tip-off that gangster Shambhu Mandal and his associates were hiding at Parvatti mohalla.
"Shambhu and Kanu Mandal managed to flee, but two persons - Dipak Mandal and Tinku Mandal were arrested with the bombs and the explosive material," Kumar said.
The SSP added that the gang used to make bombs and sell them to criminals.