The deceased was identified as Ayub Ali, 55, son of Abdur Rahman in Rail Colony area of the upazila.
ATM Golam Rosul, officer-in-charge of the Detective Branch, said as a sequel to the enmity, the supporters of the two groups attacked each other after midnight, leaving Ayub injured.
Informed by locals, DB police rescued Ayub and took to M Abdur Rahim Hospital where doctor declared him dead, the OC added.
He also said that DB police fired seven rounds of bullets to cool the situation.
A shutter gun, two rounds of bullet, two cocktails, two draggesr and 200 Yaba tablets were recovered from the spot.
A case was filed.