By Subir Bhaumik
BBC News, Calcutta
Villagers have attacked the warehouse of a shop selling subsidised grain in India's West Bengal state.
The government subsidises the cost of rice and wheat for the poor
The angry mob in Bankura district was protesting against corruption in the public food distribution system.
So-called fair-price shops, commonly known as ration shops, operate under license from the state government to sell subsidised grain to India's poor.
But a recent government inquiry found that grain was being stolen on a huge scale and sold on the black market.
Trouble began on Sunday when thousands of angry villagers attacked ration shop dealers in the villages of Sonamukhi and Kotalpukur in Bankura district.
Police fired on protesters in Sonamukhi to save a dealer from the mob. Six villagers were injured in the violence.
The protesters say the dealers stopped selling government-subsidised grain several months ago. They accuse the dealers of selling it on the black market for huge profit.
West Bengal's poor track record on the theft of public grain is second only to that of the northern state of Uttar Pradesh, the authorities say.
According to data released by the government, wheat and rice meant for rural poor worth more than $800m was stolen in Uttar Pradesh in the last financial year. West Bengal came next, with stolen rice and wheat worth $467m.
Leaders of West Bengal's governing Marxist group blame ultra-left Maoists and other opposition parties for provoking the violence.
But opposition politicians accuse the Marxists of patronising the corrupt dealers.