Maoists torched 30 vehicles of the Central Coalfield Limited (CCL) engaged in mining work in Jharkhand's Bokaro district, police said on Saturday.
More than 100 Maoists on Friday night raided the CCL project site at Bermo area of the district, some 130 km from Ranchi.
After thrashing the security men and asking them to leave, Maoists set on fire the vehicles.
Police have launched an operation to nab them. Maoists are active in 18 of the 24 districts of the state.