"The ambush was followed by a gun battle that lasted more than five hours," he said. "Fifteen security personnel have been injured."
Four of the killed were from the Central Reserve Police Force. Helicopters could not land at the spot to take out the injured due to bad weather at night.
It was not clear who the other two dead security personnel were.
Additional forces sent Tuesday rescued some of the injured and recovered two bodies.
Police say the guerrillas occupied a vantage point as they fired at the unsuspecting security forces.
Maoists are known to be active in 18 of Jharkhand's 24 districts.