Indians are voting in four north-eastern states in the second phase of the general election which pits the governing Congress party against the Hindu nationalist BJP.
Polling is taking place in six constituencies in Nagaland, Manipur, Arunachal Pradesh and Meghalaya states.
The nine-phase election got under way on Monday and will conclude on 12 May. Votes will be counted on 16 May.
Arunachal Pradesh is also voting for 49 of its 60 assembly seats.
Polling in the state of Mizoram state has been postponed to 11 April due to a strike.
The ruling Congress party has a strong presence in most of the north-eastern states, but the main opposition Bharatiya Janata Party (BJP) is hoping to make inroads there.
The BJP's prime ministerial candidate Narendra Modi and Congress vice-president Rahul Gandhi have both campaigned in the north-eastern states.
Previous elections in the region have been marred by sporadic violence and several separatist groups, active in the north-eastern states, have threatened to disrupt the ongoing elections.
Security has been tightened in all the states voting on Wednesday, the Press Trust of India news agency reports.
More than 814 million Indians are eligible to vote in a poll dominated by corruption and high inflation.