Maoist rebels are active in Chattisgarh
The beginning of a crucial round of state elections in India has been marred by outbreaks of violence.
Maoist rebels snatched voting machines and seized poll workers in the central state of Chattisgarh, police say.
Police said they fought gun battles with rebels in several places in the state. At least two members of the security forces were killed.
The election is the first in a series of votes that may determine whether the government calls an early general poll.
A general election must be held by May but could be called earlier.
Voting in six mostly central and western states will take place over six weeks, amid signs of economic slowdown.
Chattisgarh is one of at least 13 states in India where Maoist rebels are active.
14 and 20 November: Chattisgarh
27 November: Madhya Pradesh
17 November to 24 December: Jammu and Kashmir
29 November: Delhi
2 December: Mizoram
4 December: Rajasthan
In the first stage of voting in Chattisgarh, voters cast their ballots in 39 of 90 constituencies.
In the Konta and Narayanpur areas in the state's Bastar district where the rebels have a strong presence, Maoists stopped polling officials travelling to the polling stations and stole electronic voting machines, police said.
Rebels also abducted polling officials in the Katekalyan area, police said.
An air force engineer was killed when rebels fired on a helicopter in Jagdalpur district, officials said. A member of the paramilitary Central Reserve Police Force was killed in a clash with rebels in Dantewada district.
There were also at least two landmine blasts set off by the rebels which several security personnel injured, reports said.
But voting was held peacefully in other parts of the state. India's Election Commission said 55% of the 6.3 million voters registered to take part in the first round in Chhatisgarh had cast ballots.
Correspondents say that key issues in the state elections include rising prices and security following a spate of bomb attacks blamed mostly on Islamist militants.
Apart from Chattisgarh, the states that will go to the polls are Madhya Pradesh, Delhi, Mizoram in the north-east and the western desert state of Rajasthan.
For security reasons the disputed region of Jammu and Kashmir will vote in seven phases over nearly as many weeks.
If the governing Congress party does well, it may want to build on the results and call an early poll in February.
However, a poor performance might prompt the government to delay the vote until May, the end of its five-year parliamentary term.
Whichever party, Congress or the main opposition BJP, does better may find it easier to secure alliances with regional parties before the general election - of the utmost importance when building a post-election governing coalition.
The BJP faces a tough challenge from Congress in Madhya Pradesh, Chattisgarh and Rajasthan because incumbent administrations in Indian states often do badly in elections.
Observers will also be closely watching the outcome of the vote in Indian-administered Kashmir, which during the summer was the scene of large anti-India protests.
Many Indian cities, including Bangalore, Jaipur, Ahmedabad and the capital, Delhi, have been hit by bomb blasts recently, with large losses of life.
The BJP has been campaigning for a tougher anti-terror law in response to the bombings.
Counting of votes will take place on 8 December, apart from in Indian-administered Kashmir where votes will be tallied on 28 December.