Indians are voting in the third phase of the country's general election, amid campaigning by Prime Minister Narendra Modi's Hindu nationalist party and the opposition that has been marred by bitter accusations and acrimony.
People lined up outside voting stations at several places even before the polling started at 7 am.
The voting for 117 parliamentary seats in 13 states and two Union Territories on Tuesday means polls are half finished for 543-seat lower house of Parliament.
The voting over seven phases ends on May 19, with counting scheduled to begin May 23.
The voting is staggered to facilitate movement of security forces to oversee an orderly election and avoid vote fraud.
The election is seen as a referendum on Modi's five-year rule. He has adopted a nationalist pitch trying to win the majority Hindu votes by projecting a tough stance against Islamic neighbour Pakistan.
Hindus comprise about 80 per cent and Muslims 16 per cent of India's 1.3 billion people.
The opposition is challenging him for a high unemployment rate of 6.1 per cent and farmers' distress aggravated by low crop prices.
Tuesday's voting is important for Modi's Bharatiya Janata Party, which won more than half of 117 seats from these states in the 2014 elections that voted it to power.
Its performance will have a bearing on its bid to retain power in New Delhi.
Australian Associated Press