Initial reports coming from the location, somewhere along the Indo-Bangladesh border, suggest that the jawan, Prabhakar Mishra, allegedly shot the officials and colleagues from his service weapon around 10:30 am and later shot himself at Hathi Char border post, a senior BSF official said.
The jawan is reported to be critical and an air evacuation mission is currently underway to rescue the injured.
The two dead are assistant sub-inspector rank officers -- Babu Lal and Surender -- of the force. The injured has been identified as constable Om Prakash, they said.
The exact reason for the incident is yet to be ascertained, the official said.
Senior officials of the paramilitary force have rushed to the border post which is close to the Brahmaputra river.
This incident is the third fratricide incident in the last few months in the border guarding force as earlier incidents were reported from Punjab and Rajasthan.
The Border Security Force is manning the Indo-Bangla border in this region.
Photograph: Reuters