Voter turnout on Tuesday was 50-55%, according to the Election Commission.
For the first time, electronic voting machines are being used in all the constituencies across India, in the five-phased elections which began on Tuesday. These machines had been used only in select constituencies in previous elections.
Election officials transported about one million computerised voting machines to 188,975 polling places, some in deserts, remote hilltops or Himalayan valleys.
"I am excited that I am not lagging behind but also operating a modern machine," said farmer Babul Deka in the northeastern state of Assam.
But the machines developed problems in some parts of the country, forcing voting to be suspended briefly while they were fixed.
Troops were deployed in some
The election will be staggered in five phases over three weeks ending 10 May to accommodate the country's 660 million eligible voters, with counting to begin three days later.
About 400,000 police and troops were deployed to protect candidates, voters and poll workers, and air force helicopters patrolled some of the more threatened districts.
In the run-up to the polls, rebels from the disputed province of Kashmir to India's isolated northeast had promised to sabotage the vote, a gigantic undertaking in the world's largest democracy. At least 15 people were killed and 18 wounded in attacks across the country on Tuesday.
Still, violence is relatively routine during Indian elections - at least 100 people died in the last national poll in 1999.
Just as worrisome as violence in some places was the weather, with temperatures running as high as 45 Celsius.
In Guwahati, the capital of northeastern Assam state, flooding in the last 10 days meant officials had to reach polling stations by boat, bullock cart and elephant
"I am excited that I am not lagging behind but also operating a modern machine"
Voters appeared ready to reward Prime Minister Atal Bihari Vajpayee for the booming economy and the best prospects in years for peace with rival Pakistan.
"I came to vote because I wanted to recognise the good work done by the government," said Mohanlal Pashan, 70, a retired state employee in Bangalore, India's information technology hub. "For me, the most important issue is economic progress."
Opinion polls have predicted Vajpayee's National Democratic Alliance will return to power, but his party was not expected to win an outright majority and could even lose a few seats.
The opposition Congress party, which headed India for nearly four straight decades under the leadership of the Nehru-Gandhi dynasty, faces an uphill battle.