Opposition activists carried out the sudden attack at Gurnobhain in Patia’s Kusumpura union around 10pm on Saturday, police said.
The attackers used bricks to hit the victim, Dwin Mohammad, 26, Patia Police Station OC Niamat Ullah told bdnews24.com.
Businessman Enamul’s main rival is the Awami League’s Shamsul Hoque Chowdhury MP.
No leader of the two parties and the Jubo League, the youth front of the ruling party, could be reached immediately for comments.
The killing happened hours after the Awami League expressed concerns that the BNP and its ally the Jamaat-e-Islami may try to foil the election by way of violence.
Earlier, the ruling party claimed it had lost six of its activists in attacks by the BNP.
In response to the Awami League’s allegation, the BNP claimed the ruling party goons had killed four supporters of its candidates.