The electoral fate of outgoing Speaker of the Lok Sabha, Meira Kumar, former Kerala governor Nikhil Kumar and Chirag Paswan, son of LJP president Ramvilas Paswan, will be decided in the ballots.
Polling began on Thursday in six of the 40 constituencies, all in Maoist-hit areas, for the first of the six-phase Lok Sabha polls in Bihar.
The constituencies where polling is being held, starting at 7 am, are Sasaram (SC), Karakat, Aurangabad, Gaya (SC), Nawada and Jamui (SC).
About an hour and a half before the start of polling, Maoists triggered a bomb blast in Munger, killing two CRPF jawans and injuring three others, when they were on their way to a polling station in Jamui parliamentary constituency.
Of the 80 candidates, including 10 women, the electoral fate of outgoing Speaker of the Lok Sabha, Meira Kumar, former Kerala governor Nikhil Kumar and actor-turned-politician Chirag Paswan, son of LJP president Ramvilas Paswan will be decided.
Ms. Meira is seeking re-election for the third consecutive term from Sasaram, her home turf, which elected her father and Dalit icon Babu Jagjivan Ram eight times from independence to 1984.
Chirag Paswan makes his electoral debut in Jamui (SC) seat and is pitted against Assembly speaker Uday Narayan Chaudhary.
While a resurgent BJP is claiming it would bag a major chunk of the 40 seats in the state, the RJD-Congress alliance and the JD(U)-CPI alliance are equally determined to corner maximum number of seats.
Of the total electorate, women voters number 49,73,691, outnumbering male voters at 43,55,752. Altogether 9,781 polling stations have been set up.
Out of the 10,215 polling stations in the six constituencies, 3,885 have been identified as critical by Election Commission.
There are 51,000 security personnel deployed for conduct of free and fair polling in the Maoist-affected constituencies. Three helicopters have also been pressed into service for surveillance, election commission sources said. One air ambulance has been kept ready at Patna airport, an EC statement said.
A total of 94,57,323 voters, 27,52,04 of them first timers, are expected to exercise their franchise in the six constituencies.