The policemen were returning from patrols Wednesday night when the rebels detonated the land mine in the Saranda forest, in the state's Chaibasa (search) district, a police official said on condition of anonymity.
Chaibasa is about 165 miles south of Patna, capital of neighboring Bihar state.
Militants of the outlawed People's War Group were suspected of involvement in the attack, police said.
More than 6,000 people have been killed since the rebels, inspired by Chinese revolutionary leader Mao Zedong, began fighting in 1981. guerrillas are fighting for separate socialist regimes in five Indian states. They mostly target rich landowners and police.