The central states of Rajasthan, Madhya Pradesh and Chhattisgarh, and the southern state of Telangana, voted last month in the last set of provincial elections before the national poll, in which Modi will seek a third term.

BJP comfortably won Rajasthan and Chhattisgarh from the main opposition Congress and retained Madhya Pradesh, vote-counting data from the independent election panel showed.

BJP's performance was better than widely expected as opinion and exit polls had suggested a close contest between Modi's party and Congress.

Modi remains widely popular after a decade in power and surveys suggest he will win again next year. However, a 28-party opposition alliance led by the Congress has come together to jointly fight the BJP, posing a renewed challenge.

But the alliance did not feature in the state polls due to internal rivalries and it was a direct contest between BJP and Congress.

Although Congress won Telangana, its second victory in the south this year, Sunday's outcome is seen as a setback. The four states are home to more than 160 million voters and account for 82 seats in the 543-member parliament.

"We always said we will win the heartland states," BJP President Jagat Prakash Nadda told Reuters. "The results are the outcome of our finest political strategy and work on the ground."

BJP members and supporters burst firecrackers, distributed sweets and danced in the streets in the three states.

Modi told jubilant BJP members at the party headquarters the results suggested a third term next year was guaranteed.

"The results ... indicate that the people of India are firmly with politics of good governance and development, which the BJP stands for," Modi posted on X.

CONGRESS DISAPPOINTED

BJP had suffered a setback itself when it lost the big southern state of Karnataka to Congress this year, as Gandhi worked hard to revive the party since its drubbing in the 2019 election and went on a 135-day march across the country covering more than 4,000 km (2,500 miles).

He also helped build the opposition alliance, called the Indian National Developmental Inclusive Alliance or INDIA, after the Karnataka victory and his temporary disqualification from parliament after being convicted in a defamation case.

Gandhi posted on X "the battle of ideology will continue".

Congress president Mallikarjun Kharge said the party should not get "disheartened by this defeat" and should start preparing for the general elections with INDIA parties with "double enthusiasm".

Modi and leaders of Congress, led by Gandhi, criss-crossed the states, addressing campaign rallies and promising cash payouts, farm loan waivers, subsidies and insurance cover, among other incentives, to woo voters.

Politicians and analysts say state elections do not always influence the outcome of the general elections or accurately indicate national voter mood.

Results of the last round of state elections before national elections have been misleading in the past.

Sunday's outcome is, however, expected to boost market sentiment.

"Markets may have had a whiff of the likely results given the gains last week but the margin of victory will be a surprise," said Gurmeet Chadha, managing partner at asset management firm Complete Circle.

Markets should gain on Monday on the results, he said, adding it could be a "big move".

The small northeastern state of Mizoram also voted last month and votes there are due to be counted on Monday.