The members of Shanti Sena, a local resistance force formed to combat Maoist activities, were on way to headquarters town Gumla from Gumra in a vehicle when they came under a volley of fire by the ultras hiding nearby, DIG (headquarters), R K Mullick said.
As the Sena members returned the fire, the Maoists set ablaze the vehicle.
While all the eight members were killed, it was not immediately clear whether they died of bullet injuries or were burnt alive by the ultras, the official said.