The bomb fitted with a timer and planted on the road went off at around 4:25 pm when the personnel of 116th BSF battalion were on patrol at Heirok village in the foothills of the district, the sources said.
The condition of the BSF man, who first taken to the Thoubal district hospital and then to the Regional Institute of Medical Science Hospital here, was stated to be 'very critical', the sources said. His name was not known as yet.
A woman who was passing by was injured by splinters, they said.
Additional security personnel and police forces launched a search operation in the area.
In another incident, suspected insurgents hurled a grenade at the residential complex of the commandant of the Border Road Taskforce at Lamphel area in Imphal West district, the sources said.
Yesterday, a powerful bomb had exploded in the complex of the Research and Analysis Wing and Special Bureau in Lamphel area, but there was no casualty.
The banned Revolutionary People's Front had claimed responsibility saying that it was planted by its armed wing, People's Liberation Army.
