Voting is under way in India's northeastern states of Assam and Tripura which are the first two states to go to polls in a staggered election that would decide the fate of over 1.2 billion people.
People on Monday queued up to cast their votes in the world's biggest elections which will be held in nine phases, with results expected to be announced on May 16.
About 25 percent of the electorate in Assam had voted in the first three hours, while polling for the lone seat in Tripura was more than 40 percent till noon, according to the Times of India newspaper.
India's ruling Congress party, which has held power for a decade, is expected to lose after the country's 814-million-strong electorate finishes voting on May 12.
Opponents of Congress are angry about low growth, rampant corruption and religious unrest under the current government.
According to opinion polls, main opposition Bharatiya Janata Party's (BJP) prime ministerial candidate Narendra Modi is seen as the front-runner in the race with his promise of economic rejuvenation and jobs creation.
In Assam, a Congress party stronghold, some voters told the AFP news agency that they had been swayed by opposition leader Narendra Modi's promises of better infrastructure, strong leadership, jobs and a clean administration.
"My wife is a graduate, she is sitting at home without a job," Nirmal Pal, a 42-year-old car repair shop worker, told the AFP news agency in Dibrugarh. "The Congress has given us no benefit."
Rumi Nath, a 36-year-old housewife said: "I've made it a point to vote this time because we want change."
"Our area remains backward and underdeveloped 67 years after independence," she said just before casting her vote in the rural town of Lakhimpur on the Brahmaputra River.
Message of aspiration
Modi is expected to score strongly among young voters, thanks to his message of aspiration and skills over the left-leaning Congress's pitch of welfare and equitable development.
Assam's Chief Minister Tarun Gogoi of the Congress Party said he was confident of winning re-election.
"There is no Narendra Modi magic in Assam. The Congress has been winning every form of elections since 2001 in Assam, and we are going to repeat the performance this time,'' Gogoi said.
In the last general elections in 2009, Congress won seven of Assam's 14 parliamentary seats to the BJP's four, while regional parties won the rest.
Authorities deployed 25,000 police and paramilitary troopers to guard polling stations on Monday. Helicopters were put on standby, and international borders with Bangladesh and Bhutan were sealed.
"We are not taking chances," said AP Raut, Assam's police assistant director-general.
Growth under the Congress party's decade-long rule has averaged 7.6 percent per year, but a sharp slowdown since 2012 has crippled public finances and caused an investment crash.
Many Indians also believe that the second term of the prime minister, Manmohan Singh, was largely lost to indecision and scandal.
The election will be the biggest in history, as voters travel to nearly a million polling stations. Results from all 935,000 polling stations are expected on May 16.