Police discovered the bodies lying atop each other last night, Dimapur SP V Z Angami said today.
The victims were found blindfolded with hands tied behind and shot from close range on the heads, he said, adding that the bodies were covered with a blue polythene sheet over which some boulders were placed.
It was suspected they might have been killed about two weeks ago as their bodies were in a decomposed state beyond recognition.
The information about the bodies was passed on to the police by some labourers who noticed a foul smell emanating and some human feet visible.
Angami said that a case had been registered and investigation was in progress.