The BSF said in a statement that an Improvised Explosive Device (IED) went off around 1.30 p.m. inside a store situated on the roadside near the BSF headquarter campus.
The deafening blast seriously injured BSF constables Sanjay Tirkey and N.N. Meetei, amputating the lower parts of their bodies.
They were rushed to the RIMS Hospital here where both men succumbed to their injuries, the statement said.
A civilian, a female owner of the store, was also severely injured in the blast and was also evacuated to the hospital.
Earlier, police sources had said that two women, both civilians, were seriously wounded in the blast.