Some of the Bangladeshi intruders assaulted BSF jawan Nirbhay Chaube when he tried to stop them from entering into the Indian territory, he said.
The incident took place near Seema Suraksha Bal (SSB)'s 121st battalion border police outpost.
Before the injured jawan could raise alarm for help from his colleagues, the about 60 Bangladeshi intruders, retreated in their own territory, the official said.
Chaube, a native of West Champaran district, has been admitted to Kishanganj Medical College.
