According to reports, at least eight human skeletal remains were found at a construction site in Imphal, Manipur, on 26 December.
There have reportedly been over 1,500 fake encounter killings that are currently under investigation and pending with the Supreme Court.
In an NDTV report, Md Baniyamin, general secretary of Families of the Involuntarily Disappeared's Association, Manipur, said:
The fact is that the school complex where the eight skulls and skeletons were recovered were previously occupied by both central paramilitary forces and state police commandos as their outpost during the height of counter-insurgency operations in Imphal where cases of involuntarily disappeared occurred.
The remains have been taken in for forensic testing.
Manipur University's anthropology department estimated that the remains could be anywhere between 17 and 40 years old.
NDTV quoted statements by human rights activists who want "a thorough enquiry in the case".
"Who knows how many skulls are still to be unearthed, which hold with them stories which could be heinous or not, this need[s] to be found out," said human rights activist Babloo Loitongbam. "It is the responsibility of government to conduct a proper inquiry after carrying out scientific excavation."
As per the Hindusthan Times, the Manipur People's Party (MPP) has taken up the matter, and has tasked state authorities to explain where the remains came from within seven days.
"The recovery of the skeletal remains including human skulls reminds us [of] the olden day proverb 'secrets never remains as secret'," said N. Sovakiran, the MPP's president of opposition.
"MPP will lodge a complaint with the National Human Rights Commission and the Union Ministry of Home Affairs into the matter," he added.
Loitongbam alleged: "This is very possibly the graveyard of fake encounters. It is located close to the Kangla Fort, which was the site of many joint interrogations and torture."