The policemen were returning from a search operation in Palamau district of Jharkhand state when the land mine blew up their vehicle late Wednesday.
Four policemen died instantly while three others died in a local hospital, said S. N. Pradhan, the police official, the Associated Press reported on Thursday.
The rebels have been fighting for more than three decades in central and eastern India to demand a greater share of the region’s natural resources for its indigenous peoples. They have been relatively quiet over the past six months.
The rebels say they are inspired by Chinese revolutionary leader Mao Zedong. The Indian government says the rebels are the country’s most serious internal security threat. India’s home ministry says the rebels are active in 20 of India’s 29 states.