Both the personnel have been injured and rushed to hospital.
Officials said the incident occured at about 1230 AM at a company location of the Central Reserve Police Force in Latehar's Kone area when constable Mahipal and Head Constable Sanjay picked up a fight.
Soon after, they said, Mahipal allegedly shot Sanjay using an INSAS rifle kept in the camp and later shot himself too from the same weapon.
While Mahipal worked as a barber in the unit, Sanjay was posted as a driver.
"We are trying to ascertain if this a case of fratricide or weapon mis-handling by the troops involved. Senior force officers in Latehar have reached the spot along with state police and are investigating," the official said.
They said both the troops belonged to the 214th battalion of the CRPF deployed in the area for anti-Naxal operations and other security duties.