Tens of thousands of people, including many women, stood in serpentine queues at polling stations since early Wednesday to cast their ballot in the third phase of the staggered Bihar assembly elections.
Around 12 percent polling was recorded in the initial hours in the assembly elections being held at 50 constituencies.
No violence has so far been reported, officials said.
Voters turned up at many polling stations in Bihar hours before the start of ballotting.
"Initially queues were small. Now voters are standing in long queues outside polling booths," said an official at the chief electoral office here.
Polling began at 7 a.m. in 50 of the 243 constituencies, including Maoist-affected areas, spread across six districts, officials said.
"Around 12 percent of 14.5 million voters eligible to cast their ballot had voted in the first two hour hours," the official said.
"Polling will pick up like the first phase polls on last Monday."
The six districts where polling is being held are Patna, Saran, Vaishali, Nalanda, Bhojpur and Buxar.
RJD chief Lalu Prasad along with his family including wife and former chief minister Rabri Devi and daughter Misa Bharti and son Tej Pratap cast their votes in Patna on Wednesday.
Lalu was clad in his usual cotton kurta and payjama. He was accompanied with Rabri Devi, Misa and Tej Pratap who cast their vote at a polling booth in veterinary college under Digha assembly constituency in Patna.
"Modi is playing the communal card on reservation. People in the country never expected such words from the prime minister," Lalu said after casting his ballot.
He was referring to Modi's statement during his election rallies on Monday and Tuesday that it was not BJP-led NDA but Lalu-Nitish and Congress who are a threat to continuance of reservation in the future and they will provide reservation to a religious community.
"No one can change or snatch reservation of Dalits and OBCs in the country."
He said Modi and BJP leaders have been nervous after reports of their defeat in the polls and added that the grand alliance of JD-U, RJD and Congress is sweeping the ongoing Bihar assembly polls and would form the next government.
Senior BJP leader and former deputy chief minister Sushil Kumar Modi has also cast his vote here.
Chief Minister Nitish Kumar will cast his vote at a polling booth in Bakhtiyarpur assembly constituency in Patna.
Bihar police chief P.K. Thakur told the media here that so far polling is peaceful with no report of violence, barring minor clashes between rivals.
At some places, the electronic voting machines malfunctioned. Apart from that, it was a smooth exercise in a state notorious for election violence.
Officials said that voters in over a dozen villages in Patna, Vaishali, Bhojpur, Saran and Nalanda boycotted polls and shouted slogans against the lack of development.
Two helicopters, drones and 667 companies of paramilitary forces have been deployed for the polls, Additional Chief Electoral Officer R. Lakshmanan said.
The Election Commission has cut down polling hours in the sensitive areas till 4 p.m.
According to the Association for Democratic Reforms and the National Election Watch, 215 candidates in the third round face serious criminal charges including those of murder.
The staggered elections to pick a 243-member Bihar assembly will end on November 5. The result will be revealed three days later.
In the first and second phases of the elections on October 12 and 16, polling was held in 49 and 32 constituencies. The fourth round will be held on November 1.
Read everything you need to know about third phase of assembly elections