The Bijepur Assembly seat is set to go to polls tomorrow and the counting of votes will take place on February 28.
The death of Congress MLA Subal Sahu in August a year ago necessitated the Bijepur bypoll.
A series of violent incidents, including an attack on the brother of state Labour Minister Sushant Singh late Thursday, heightened threat perception ahead of the bye-election.
Briefing reporters at Bargarh, inspector general of police (northern range) Sushanta Nath said three persons, including Basudeb Naik who had unsuccessfully contested the last zila parishad election in Bargarh district, had been arrested.
All of the injured were initially rushed to community health centre at Sohela and later shifted to VIMSAR Medical College and Hospital in Burla as their condition deteriorated. The BJD leaders alleged this incident follows earlier incidents in which the BJP workers threw eggs on the Chief Minister at Talasari in Balasore district and shoes were hurled at him in Kumbhari village of Barpali block. "As it is a peaceful state, the people of Odisha will give befitting reply to the criminals responsible for this murder", Patnaik said. "While three persons have been arrested, two police teams have been formed to nab others involved in the incident", said additional superintendent of police (SP) Jashobanta Senapati.
While the BJD MLA, Debesh Acharya alleged that the attack wasn't done by a sole spectator but it was the BJP government that had a major role to play.
The aggressive campaigning by the rivals, BJD and BJP, was not unexpected in view of the stakes involved for both the political parties. His party MLA Pradeep Purohit also accused the BJD of making baseless allegations against the BJP.
"The attack was fallout of rivalry between two political groups".
Elaborate security arrangements have been made for the bypoll in the constituency located in Bargarh district, especially in the wake of pre-poll violence in and around the area, officials said.
A delegation of the BJP also moved the Chief Electoral Officer and sought installation of CCTV cameras in all sensitive booths in the Assembly constituency.