Amnesty International is urging India to allow impartial forensic experts to investigate hundreds of unmarked graves in Kashmir.
Officials have previously claimed the graves contain the bodies of militants fighting the government. But the government now says civilians killed in the 20-year-old conflict may also be buried there.
A statement from London-based Amnesty International late on Monday called for an independent investigation.
Last week, the government confirmed more than 2,000 unidentified bodies had been found in single and mass graves in three northern regions.
Another 574 bodies found in the graves have been identified as local residents.