According to reports, the foreign-made remote-controlled bomb exploded at Lokchao along the Trans Asian Highway 102.
The personnel of the 165 Territorial Army were passing by when the bomb was detonated, the official said.
The injured were shifted to an army hospital at Leimakhong near the state capital. A helicopter was pressed into service to air-lift at least four of the injured personnel.
Police suspect there could be several casualties.