Officials said the incident was reported from the Badrakusi-Tihu area in the district where a platoon of the 136th battalion of the Central Reserve Police Force (CRPF) was out on duty along with local police.
They said the accused jawan, Head Constable Amal K Das used his service weapon to shoot at his officer and Assistant Sub-inspector (ASI) D C Bandolai and injure four other men after he had some altercation with his collegaues.
The injured troops have been identified as constables Mohale Janardan of Maharashtra and Diganto K Banya of Assam, Head Constable Dayaram Bandaloi and ASI Nirmal Das, both residents of Assam.
Senior officials of the paramilitary and local police have reached the spot even as CRPF has ordered a Court of Inquiry into the fratricidal incident.
The force is deployed in the state for assisting local police in rendering law and order duties while some of its special units also conduct special counter-insurgency operations.