Indian Prime Minister Narendra Modi's ruling party routed the main opposition in key heartland states as votes were counted Sunday, months before national elections in the world's most populous country.

The victories in three of the five states that voted in November further boosted the right-wing Bharatiya Janata Party and Modi, who is already the favorite to win his third consecutive term in office next year.

The premier's party wrested control of Chhattisgarh and Rajasthan states from the opposition and retained Madhya Pradesh in a landslide despite a spirited challenge.

The results are seen as yet another setback for the Nehru-Gandhi dynasty scion Rahul Gandhi, 53, who led the opposition center-left Indian National Congress party's aggressive and personal campaign directly targeting Modi.

Gandhi's father, grandmother, and great-grandfather were prime ministers and political stalwarts who dominated the Indian political landscape for decades. 

India's once-dominant political force, the Congress party, lost the last two successive national elections in 2014 and 2019 in historic defeats to Modi and the BJP. 

The Congress defeated the regional BHRS (Bharat Rashtra Samithi) party in the southern state of Telangana while votes in the small northeast Indian state of Mizoram will be counted on Monday. 

Modi, who remains widely popular in his tenth year in office, flew across all poll-bound states in October and November to address tens of thousands of people in packed campaign rallies.

With the final votes still being counted, India's election commission Sunday evening said that the BJP had won or was leading in 163 of Madhya Pradesh's 230 state assembly seats.  

In Rajasthan, the BJP had 115 wins and leads in the 199-member legislature, and the party was set to secure 54 of 90 seats in Chhattisgarh. 

"Today's victory is historic, it is unprecedented," Modi said in a victory speech at the BJP headquarters in New Delhi on Sunday. 

"I bow to the people for their support. It is for our politics of good governance and developed India," he added. 

The states won by the BJP have about 190 million voters and elect dozens of members to the national parliament.