Repoll was held at 33 polling booths spread over five Lok Sabha constituencies in the state, which went to polls in the first phase on April 10.
The Maoists ambushed the poll personnel near Hadhadwa forest under Kauakol police station area when they were returning after conducting repoll at Dania polling station area in Nawada constituency.
"The Maoists suddenly attacked the polling party. The security forces accompanying them retaliated. The firing lasted for a few minutes. Nobody was injured in the incident and all our people are safe," said Additional Chief Electoral Officer R Lakshmanan.
All polling stations were in Maoist-affected areas and voting was conducted from 7 am to 3 pm, but voter turnout was low, EC officials said adding these constituencies had gone to poll last Thursday during the first phase of polling in Bihar.
"The voting percentage was 42.44 in today's repoll, with the highest being 54 per cent at Aurangabad and the lowest being 29 per cent in Jamui," Lakshmanan said.
Meanwhile the EC registered 19 cases of violation of the Model Code of Conduct across the state today. Security forces seized nine weapons and 30 cartridges and executed 781 non-bailable warrants.