Umar Abd Allah, chief of disputed Kashmir's pro-India National Conference party, escaped a bid on his life when a landmine exploded minutes after his campaign convoy passed, police said.
A policeman was wounded in the attack on Abd Allah, a former junior foreign minister, they said.
A vehicle ran over a landmine in Kashmir's Lolab area, killing one passenger and wounding six other people. Police said the victim had not yet been identified.
Lolab is part of Kashmir's Baramulla constituency that voted on Tuesday. Separatists also attacked polling stations in Baramulla overnight and hours before polling began, killing two policemen standing guard.
Kashmiri fighters and political separatists say the election is no substitute for a resolution of the 57-year-old conflict over the Himalayan region where a revolt has killed tens of thousands.
Separatist guerrillas killed four soldiers, burnt electoral rolls and voting machines in the remote northeastern state of Manipur, which borders Myanmar. The fighters have threatened to kill anyone taking part in the election.
Tens of thousands of soldiers backed by surveillance aircraft were deployed across 13 states and three federally administered territories which voted on Tuesday.
Vajpayee is widely expected to
win by a narrow majorty
Balloting in the first phase of India's marathon election ended on Tuesday after tens of millions of people voted across 13 states and three federal territories, poll officials said.
The 10-hour voting ended at 5:00pm (1130 GMT) in 140 of the 543 parliamentary constituencies up for grabs.
Four more days of polling ending on 10 May are scheduled to allow police and troops to move across the vast nation to ensure security during the vote. The votes will be counted on 13 May. More than 175 million people are eligible to vote in 186,000 polling booths staffed by nearly a million officials.
Prime Minister Atal Behari Vajpayee's Bharatiya Janata Party-led coalition is predicted to win a narrow majority and defeat the opposition Congress party of Italian-born Sonia Gandhi, widow of assassinated prime minister Rajiv Gandhi.
At least 35 people were killed during elections in 1999 and 64 died in polls the previous year.