About 100 militants surrounded a post of 35th Assam Rifles at Aigejang hill area in interior Chandel district yesterday and fired at the personnel.
The paramilitary personnel returned the fire and an encounter ensued for about an hour, they said adding that the militants fled under forest cover.
There was no casualty on the side of the forces.
Militants of another outfit exploded a powerful improvised explosive device bomb near the post of 39th Assam Rifles personnel who were patrolling Behiang area at Indo-Myanmar border yesterday.
It was not clear if the attack was linked with the monetary demand from the bank official.