Deputy Superintendent of Police, Khargpur, Ranjan Kumar told PTI that the security personnel belonging to 131 CRPF battalion were travelling in two jeeps to Tarapur in the Maoist-affected district for poll duty in the early hours when the attack took place.
The Maoists first detonated an improvised explosive device and then ambushed the CRPF personnel near Sawa Lakh Baba Mandir at the entrance of Bhimbandh jungle at around 5.30 AM. The security personnel returned the ultras' fire.
The seven injured have been rushed to Bhagalpur hospital, he said.
Maoists had earlier given a call for a poll boycott.
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