At least 20 people have been killed in poll-related violence as millions of voters turned out to cast their ballots in three Indian states.
Voting is taking place under tight security
Fourteen people were killed in violence between troops and suspected Maoist rebels in the eastern Indian state of Jharkhand.
At least six people were also been killed in poll violence in the neighbouring state of Bihar.
Voting also took place in the northern state of Haryana.
Six policemen and their driver were killed in a landmine attack when they were returning from a polling station in Jharkhand's Palamau district, one of 24 constituencies in the state for which voting took place on Thursday.
Police blamed Maoist rebels for carrying out the attack.
In another incident, three paramilitary soldiers and four Maoist rebels were killed in a clash in the same district.
In neighbouring Bihar, the authorities say Maoist rebels attacked a police team in Gaya, killing two policemen and a civilian.
In a separate incident, two civilians were killed when police opened fire to disperse a mob that had attacked a polling station in Sasaram district.
One person was also killed in an attack blamed on Maoist rebels in Jehanabad.
Heavy security was in place in Jharkhand and Bihar, two of India's poorest states with a history of poll violence.
About 40,000 paramilitary soldiers were deployed in the two states besides tens of thousands of local police.
Voting has been spread over three phases in the two states on account of the security situation.
But voting took place in all 90 assembly constituencies in the prosperous state of Haryana, which borders the national capital Delhi.
The BBC's Asit Jolly reports that voters reached polling stations early despite the cold weather.
Congress and its allies are hoping to perform strongly in all three states, following their surprise victory in last year's national elections in which they handed a shock defeat to the right-wing Bharatiya Janata Party (BJP).
While Congress hopes to unseat a regional party governing Haryana, it is looking to oust the BJP from Jharkhand.
Bihar is governed by one of the Congress' main allies, the regional Rashtriya Janata Dal party of Laloo Prasad Yadav, one of India's most popular and colourful politicians and a senior member of the federal cabinet.