Maoist guerrillas torched at least six vehicles and blasted a forest office in Jharkhand's Seraikela-Kharsawa district early on Friday, police said in Ranchi.
10-15 Maoists raided Harangada village and set ablaze the vehicles of the Surusi water reservoir project.
Reports cited denial of extortion money as the reason for vehicles being torched. Maoists also left behind a leaflet warning of similar incidents if work not stopped.
This year, more than 60 vehicles have been torched by the militants in the state.
Maoist guerillas are active in 18 of the 22 districts of the state.