"The incident occurred in morning hours between Tarlaguda and Annaram villages under Tarlaguda police station limits," Bijapur Additional Superintendent of Police Mohit Garg told PTI.
A road is being constructed between Tarlaguda and Annaram, located over 450 kms away from here.
A group of armed ultras first made the workers leave the spot before torching around 15 vehicles and machines, including tractors and a JCB machine, and fled into forest.
A combing operation is underway to trace the naxals.