The Jharkhand Police on Saturday recovered explosives during an anti-Maoist operation in the state, while extremists set on fire six vehicles in Bastar district of Chhattisgarh in protest against the development activities in the area.According to the police, the explosives were recovered from Kumari village of Gumla district in Jharkhand during the operation which was launched based on information on movement of Maoist guerrillas.Six bombs, Maoist uniforms, pamphlets, a printer, a blood pressure monitoring device and some other articles were seized from the location.Maoist guerrillas are active in 18 of the 24 districts of Jharkhand.In the other incident, Moists set on fire six vehicles, including two tractors and one JCB, engaged in road construction work in Dantewada district of Chhattisgarh.They have also been protesting against the ongoing development activities in Bastar district.Additional Superintendent of Police G.N. Baghel said: "Road construction work was going on under the PMGSY programme in Toylanka village, 25 km away from the district headquarters, when around half-a-dozen Maoists came and forcibly stopped the work there."They took diesel out of the tractors and set the vehicles on fire and also warned the labourers to stay away from the construction work, Baghel added.