Last night four suspected militants arrived at the residence of Kamei Pumdai (48) at Nungsai Tubung village where the heavy machinery was kept and set them afire.
The excavator and the bulldozer were being used for repairing Old Cachar road in the district.
The incident occurred when Pumdai's family members were asleep, the police said.
They were alerted when the some shots were fired during the burning of the machinery. Local residents entered the area but they were threatned not to extinguish the fire, the police said.
No individual or group has claimed responsibility for the incident.
