Landlords with rifles and sticks ride motorcycles menacingly across fields where peasants work - often for a wage of grain, not money.

But the hopes of many peasants are riding with communist guerrillas whose aim is the violent overthrow of those they deem oppressors - the high-caste landlords of Bihar, India's poorest and most backward state.Officials concede that the landlords are a law unto themselves in Bihar and are resisting peasant demands for something better than payments in grain, a common practice in rural India.

"The landlords don't give us wages," peasant worker Mateshwari Devi said as she sat recently on the floor of her mud hut. "If we fight, they rain bullets on us. We neither have land nor grain. How are we to survive?"

In recent years, however, the Maoist guerrillas have been organizing peasants and have become enforcers, meting out their own "instant justice." Known as Naxalites after Naxalbari, the town where their movement was founded, the guerrillas have been gunning down landlords judged by them to be oppressors of the poor.

The Naxalites' "Red Army" also has clashed with the landlords' private armies, which peasant leaders and press reports say terrorize low-caste communities.

At least 205 people have died in 898 "violent incidents" in Bihar since 1983, according to official figures. News reports and civil libertarians put the toll at more than 450.

The state's 85,000-member police force has tried to stop the killings, but officials say the problem goes deeper than just establishing law and order. They maintain it stems from the abject poverty of the low-caste masses and alleged injustices of landlords who are almost always from the upper castes.

The caste system of hereditary social grouping was legally abolished in India in 1949, after independence from Britain, but it still fuels tensions between the haves and have-nots.

R.N. Dash, Bihar state's home secretary, said the Naxalites do get results.

"This is an economic issue, and the Naxalites provide an aggressive forum for airing peoples' grievances," he said. "When they agitate, roads get built and things happen."

Bihar's 80 million people have an annual per capita income the equivalent of $111, in contrast to a national average of $254.

In April 1987, police opened fire on a meeting of about 300 peasants and laborers, killing 23 people. Local activists charged that it came about at the instigation of K.D. Singh, a local landlord.

The rally had been called to protest Singh's claim to a tiny piece of land the government had granted to poor families.

The findings of an official inquiry were never made public. But officials, speaking on condition of anonymity, said the inquiry found the police action justified on grounds of "apprehension of breach of peace."

The activists claimed that Singh had arranged for the police to open fire and that he himself joined in the shooting.

Singh was shot to death this past Feb. 27; local people say the Naxalites killed him.

Shia Sharan, whose eldest son was killed in the shooting a year ago, said he fully supports the Naxalites' tactics. He added that he has been unsuccessful in his attempts to bring his son's killers to justice.

"I have tried everything legal. I have sent telegrams to the authorities, but no action has been taken," he said, showing a neat file of documents and newspaper clippings.