Jk Bhatt, police superintendent, said officers and villagers had recovered the remains of six bodies and were trying to figure out how many more were in the grave in Lunawada, a village in the state of Gujarat.
"It is still not clear whether the bodies were buried by relatives during chaos of the riots or they were dumped by rioters," he said on Tuesday. "We are investigating."
He did not say why people from the village, where the victims are thought to have come from, would just now be uncovering a grave site filled with family members they themselves buried.
Gujarat was the site of one of India's most violent religious riots, sparked in February 2002 by an attack on a train car in which 60 Hindus returning from a religious pilgrimage were burned to death.
Muslims were blamed for the fire, and more than 1000 people, most of them Muslim, were killed by Hindu mobs in the ensuing violence.
|Over 1000 people, mostly Muslim, |
were killed in the ensuing violence
However, a government inquiry released a report in January which concluded that the fire was started by accident.
Evidence suggests the fire began inside the train, not that it was fire-bombed, an investigating judge decided.
Human rights groups have accused the state government, led by the Hindu-nationalist Bharatiya Janata Party, of doing little to stop the violence, and the Supreme Court has criticised the state's lenient handling of Hindus accused of killing Muslims.
Many victims were buried in mass graves - some dug by killers, others by relatives - and authorities were alerted to the latest find by villagers who found it on the outskirts of Lunawada, about 172km southwest of Ahmadabad, the capital of Gujarat, Bhatt said.
He did not say exactly when the grave was found or explain why villagers were digging at the site.
Amit Shah, the state's junior home minister, told the Associated Press on Tuesday that the police were expected to report back to officials about the mass grave in the next day.