Unidentified persons exploded a bomb and opened indiscriminate fire at two polling booths in Chapra soon after polling began for 17 of the 40 Lok Sabha seats in Bihar on Monday.
However, no one was injured in the attacks, police said.
The bomb explosion took place at Damodarpur-Sikatia, while unidentified persons fired at a polling station at Barwe, they said.
RJD supremo Laloo Prasad Yadav is pitted against Civil Aviation Minister Rajiv Pratap Rudy in a keen contest in Chapra.