Madhepura: An estimated 50 to 52 per cent voters exercised their franchise in the by-poll for Madhepura Lok Sabha constituency, which passed off peacefully amid tight security.

District magistrate-cum-returning officer for Madhepura Prem Singh Meena said the balloting remained "smooth and incident free."

Seven persons were arrested at different places in the constituency for trying to vitiate the polling.

Meena said about 50 to 52 per cent voters exercised their franchise in Madhepura where incarcerated RJD (Rashtriya Janata Dal) candidate Rajesh Ranjan alias Pappu Yadav locked horns with his JDU (Janata Dal United) rival R P Yadav. Pappu Yadav is currently lodged in the high-security Beur jail in Patna in connection with the CPM (Communist Party of India-Marxist) MLA Ajit Sarkar murder case.

There were complaints of defects in electronic voting machines (EVMs) from some booths in the morning, which were rectified promptly, he said.

Not much enthusiasm was seen among the voters in the constituency where 40 companies of central forces were deployed to effectively tackle law and order problems.

Meanwhile, JDU has accused ruling RJD of unleashing "terror and capturing booths" at several places and called for re-poll in 57 booths.

"RJD activists unleashed terror to intimidate the voters and captured booths at several places in Madhepura," State JDU spokesman Sanjay Verma said.

Verma expressed hope that his party nominee R P Yadav would emerge victorious from Madhepura.