Voting begins on Tuesday in the first stage of a mammoth exercise involving over 670 million voters, who are expected to give the ruling Hindu nationalist-led coalition a new five-year term to rule.
Freedom fighter in occupied Kashmir and leftist guerrillas in the impoverished eastern and southern parts of the country have urged people to stay away from the election, saying it was not a solution to their grievances.
Leftist guerrillas set off a landmine in the southern state of Andhra Pradesh on Sunday night, wounding a leader of a regional group backing the federal coalition. But the independent Election Commission said it had taken adequate precautions.
"All arrangements are in place, voters are urged to exercise their franchise freely and without any fear," it said in a statement.
Occupation police detained about 50 anti-election protesters in occupied Srinagar, where supporters of freedom movement have urged a boycott saying the polls were no substitute for a resolution of the 57-year-old dispute over the region.
Freedom fighters have carried out a series of attacks in occupied Kashmir ahead of the election, killing 11 people and wounding more than 60 others in a grenade attack on a campaign rally on April 8.
They have warned Kashmiris of dire consequences if they take part in the polls.
"I won't risk my life for these elections," said Ghulam Din, a resident of northern Baramulla.
Two occupied Kashmir constituencies vote on Tuesday.
Meanwhile, suspected freedom fighters narrowly missed former puppet chief minister Farooq Abdullah in a grenade attack on Monday, occupation police said.
No one was hurt in the attack. No further details were immediately available.
Tuesday's voting will take place in 13 of 29 states - including occupied Kashmir and the western state of Gujarat where tensions between Hindus and Muslims remain high, two years after the country's worst religious bloodletting in a decade.
Officials have ordered air surveillance over the eastern states of Jharkhand and Bihar where outlawed leftist guerrillas have threatened to kill anyone coming out to vote.
Opinion polls have predicted a clear win for Prime Minister Atal Behari Vajpayee's Bharatiya Janata Party-led coalition, but a new survey said main challenger Congress had narrowed the gap.
Vajpayee's BJP has dropped its hard-line Hindu agenda, and is campaigning on a feel-good platform of strong economic growth, governance and peace prospects with Pakistan.
The main opposition Congress led by the Italian-born Sonia Gandhi says the BJP, which it has long accused of a deep-seated bias against the nation's 120 million Muslims, remains a threat to the country's secular character.
India's financial markets have soared in the last year on the back of reforms and a strong economy, with the rupee at a four-year high. Analysts say markets are hoping for a convincing victory for the BJP-led coalition, which will enable them to push reforms through more aggressively.
Vajpayee, who is leading a coalition made up of more than 20 parties, has urged voters for a clear verdict to ensure political stability.
"Another 22-party government, it will not be good. The country needs stability," he said at a weekend campaign rally in the central city of Nagpur.
In latest polls, India Today magazine said the BJP-led coalition would likely take 282 seats in the 545-member lower house of parliament, more than the half required to rule but far less than 335 seats that the magazine predicted in its first survey in January.
Other polls in the last week have given the BJP-led coalition between 276 and 278 seats, but one poll by The Week magazine gave them just 248 - far below a majority.
But even if the coalition fails to get a majority, analysts say it will still emerge as the largest group and probably be able to attract smaller parties to form a government.
Polling will take place on four more days ending on May 10 to allow security forces to move across the vast nation to ensure a free and fair vote. Counting of votes is scheduled for May 13 and results are expected the same day.
Elections in India have been violent in the past, marred by clashes between rival political groups and attacks by insurgent groups fighting for either autonomy for their regions or secession.