Police have discovered unmarked graves in Nandigram where there were violent protests against the West Bengal government, raising fears the death toll may be higher than the official figures.
The state government, which is an ally of the central government, has been roiled by protests over the killing by suspected communist cadres of villagers opposed to the seizure of land for industry.
Government officials said six people had been killed over the last month in protests in Nandigram, bringing the toll to 34 since January. But some witnesses said many more deaths have been concealed.
"Human bodies seem to have been buried in a hurry and the graves need to be dug up to find the truth," Alok Raj, a senior central police officer, said.
The communists lost control of Nandigram earlier this year after trying, unsuccessfully, to get villagers to vacate their land.
Local opposition parties and Maoist rebels then moved in after villagers dug up roads and burned communist party offices.
This month, communist party cadres broke that resistance by forcing their way in and shooting at villagers, locals said. Opposition parties said innocent villagers who fought communist cadres were killed and their bodies carried away.
This week in a further embarrassment for the communists, West Bengal Chief Minister Buddhadeb Bhattacharjee admitted that Nandigram had been a "political and administrative failure."