About 13.5 million voters are eligible to decide the fate of 586 candidates in 49 constituencies. Samastipur, Begusarai, Khagaria, Bhagalpur, Banka, Munger, Lakhisarai, Sheikhpura, Nawada and Jamui districts are voting in the first phase.
The five-phase election for the 243-seat assembly will end on November 5. Counting will take place on November 8.
According to the Association for Democratic Reforms and the National Election Watch, as many as 130 candidates in the first round of polls face serious criminal charges including murder.