AHMEDABAD, India — The ruling party won a sweeping victory Sunday in state elections in western India -- a landslide that could boost Hindu supremacists in national politics and challenge the whole country's secular traditions.

With 125 seats, the Bharatiya Janata Party controls two-thirds of the 182-seat legislature in Gujarat.

The return of the Gujarat's BJP leader Narendra Modi as chief minister came just months after the state suffered India's worst Hindu-Muslim rioting in a decade. A thousand people were killed, mostly Muslims attacked by Hindus.

The opposition Congress party accepted defeat but accused local BJP leaders of exploiting ill-will against minority Muslims to garner support among the Hindu majority.

Critics fear that now this tactic has worked for the BJP in Gujarat, the party might use it in a series of forthcoming ballots across India, including the general election due within two years.

The crushing win is seen as aiding Prime Minister Atal Bihari Vajpayee, leader of the BJP and head of the 19-party coalition government that governs India.

Elections in 10 states are due next year, and national elections must be held before 2004. The victory by the BJP in Gujarat ends a losing streak by the prime minister's party in four state elections this year.

Chief Minister Modi reclaimed his state assembly seat in the Maninagar district of Ahmedabad, the state's commercial capital. He has been criticized for saying that Hindu revenge attacks against Muslims during the rioting this year were understandable. The rioting began in late February after a Muslim mob set fire to a train in the town of Godhra, killing 60 Hindus.

After Modi won his seat, he declared: "All pseudo-secularists have been defeated. They had unleashed a vicious campaign against my government, making all sorts of accusations after the Godhra incident.''

The Congress party win 51 seats.

"People have responded to the BJP's strident Hindu-nationalist campaign,'' said Shankersinh Vaghela, head of the party in Gujarat. "If the Congress has been defeated, we accept the verdict.''

BJP supporters began celebrating by exploding firecrackers at party headquarters in Ahmedabad, shouting, "Long live the BJP.'' Police were concerned that victory parades might lead to new clashes.