The people of Oting in Mon district in the northeastern state said they will erect a monolith in memory of the 14 people on the first anniversary of the killings.
Refuting the Army's contention that the incident was a result of mistaken identity, he said, "The ambush site was barely few metres away from the coal mining site and the villages are nearby. How could they lay an ambush so close to civilian residences?"
At least five people were killed and several others injured in a suicide attack on an army facility in northwest Pakistan on Saturday.
Lt Sushmita shot herself at her posting in Udhampur.
The CBI has registered an FIR against Colonel Raman Dahda, Lieutenant Colonel Mahendra Kumar, Subedar Devender Kumar, Havildar Abhay Singh, Subedar Sahuran Sahu and supplier K K Yangfo for criminal conspiracy.