India's main Hindu nationalist party trounced the nationally ruling Congress in four heartland states and knocked them out of the Indian capital in a ballot contest closely watched for clues to next year's general election.
The Bharatiya Janata Party, or BJP, had waged a fierce campaign fronted by its prime ministerial candidate, Narendra Modi, who has charmed businesses but worried critics that his rise could worsen sectarian tensions between India's majority Hindus and its 138 million Muslims.
Results released late Sunday showed the BJP besting Congress in northwest Rajasthan, in landlocked Madhya Pradesh and Chhattisgarh, and in the state of Delhi encompassing the Indian capital.
As the votes were being counted, BJP supporters danced and set off firecrackers outside the party's New Delhi headquarters, while the area outside Congress headquarters was deserted.
Congress spokesman Randeep Singh Surjewala called the results disappointing, conceding "we have lost." Modi offered congratulations to his BJP colleagues by Twitter.
The elections were seen as a gauge of voter sentiment in this secular democracy of 1.2 billion, where there are no reliable opinion polls and at least one-fifth of the 800 million-strong national electorate will be youths casting their first general election votes next year.
Overall, Congress was seen to lose ground due to a national focus on systematic graft marked by high-level corruption scandals and low-level bribery that is an everyday feature in routine tasks, from getting a marriage license to securing a child's place in school.
Congress - led by the descendants of India's first prime minister - also took a beating over stalled economic reforms and soaring living costs, exacerbated by an economic slowdown from growth averages above 8 percent for five years up to 2011 to below 5 percent today.
"Congress is getting it in the neck on two sides - one for not being liberal enough, not giving enough incentives to corporates," said political analyst Kamal Mitra Chenoy of Jawaharlal Nehru University. "On the other side, the poor and lower middle-class are saying, 'what about us, what are we going to get?'"
In New Delhi, Congress' Chief Minister Sheila Dikshit was denied a fourth term after presiding over the capital's growth into a megacity of nearly 17 million people, many of them impoverished migrants.
A new party called Aam Aadmi Party - or Common Man's Party - played spoiler in the race, campaigning in New Delhi's poorest neighborhoods and pushing Congress into third place. Final results gave BJP 31 seats and the debutant party 28, with Congress collecting eight.
Hundreds of AAP members danced wildly outside the party's Delhi office while holding up brooms - the party's symbol, alluding to its promise to sweep out corruption.
It was a stunning fall for Congress, which took 43 seats in the last Delhi elections.
"We accept our defeat, and we will analyze what went wrong," Dikshit told reporters after resigning.
Congress also lost control of Rajasthan, winning 21 seats to BJP's 162. In central Chhattisgargh, Congress took 39 seats and the BJP 49, while the BJP retained Madhya Pradesh 165 to 58.
The BJP's Modi, a three-time leader in Gujarat, is credited with turning his western state into an industrial haven. But critics question whether the Hindu nationalist chief can be a truly secular leader over India's many cultures defined by caste, clan, tribe or religion, including Islam, Christianity, Judaism, Hinduism, Sikhism, Jainism and Buddhism.