Nearly 32% of the electorate voted in the first six hours on Thursday in Bihar's six Lok Sabha constituencies despite incidents of violence in the state.
"So far about 32% of the electorate has voted. The polling was slow in early hours, but later picked up fast," Additional Chief Electoral Officer R. Lakshaman said.
A little over 94 lakh voters are eligible to elect from among 80 candidates, including 10 women, who are in the fray in Maoists affected constituencies.
Two Central Reserve Police Force troopers were killed in the landmine blast in Munger district when they were on way to a polling station in neighbouring Jamui parliamentary constituency.
The blast was triggered by rebels near Sawa Lakh Baba Mandir, close to Bhimbandh forest in Munger, about 175 km from here.
Additional Director General of Police Ravinder Kumar said the injured security personnel were admitted to a hospital.
After the incident, the Jamui district administration cancelled election at 12 polling booths.
Security forces also recovered two IEDs from the spot.
Also, five cane bombs - two in Gaya and three in Aurangabad parliamentary constituencies - were recovered from near polling booths.
In another incident, Maoists blasted a state-run school in Bihar's Lakhisarai district, police said, adding three live cane bombs were also recovered from the school premises.
"Maoists blasted school in Lakhisarai to create panic in neighbouring Jamui parliamentary constituency," a district police official said.
Bihar Chief Secretary A.K. Sinha said a total of 46,000 security personnel, including 22,000 home guards, 74 companies of Bihar Military Police and 163 companies of central para-military forces, have been deployed on election duty.
Sinha said three army helicopters at the disposal of the state government are being used in air surveillance of Maoist-affected areas.
Prominent candidates in the fray are: Lok Sabha Speaker Meira Kumar for Sasaram seat, Bihar assembly Speaker Uday Narain Choudhary from Jamui, former Kerala governor and Delhi Police chief Nikhil Kumar from Aurangabad, actor-turned politician Chirag Paswan from Jamui, and former union minister Kanti Singh from Karakat.