State Director General of Police Abhayanand said the three policemen belonged to the Special Auxiliary Police Unit, while the two others were private security guards deployed at the construction site.
Around 50 armed Maoists arrived at the scene and detonated bombs in a bid to destroy the culvert in the Goh area of the district. The culvert was partially damaged in the attack, the DGP said.
A gunfight followed after a police contingent arrived at the scene on getting information about the attack. The Maoists fired at the security personnel who retaliated. Casualty or injury on the side of the red rebels could not be ascertained.
A combing operation was on, the DGP added.