The deceased was identified as Asha, 34, son of late Atal Uddin of Balia village in the same upazila.
According to police and witnesses, Asha and his brother Moidul, 30, led a procession from the local BNP office in the afternoon.
As it reached the Jamtala intersection, they were obstructed by a rival group led by BNP leader Biplob, leading to a clash involving brickbats and locally made weapons.
Asha and Moidul sustained serious injuries during the clash.
They were rushed to Jashore General Hospital where doctors referred Asha to Dhaka Medical College Hospital. He later succumbed to his injuries there.
Moidul is currently receiving treatment at Jashore General Hospital.
Asha’s sister Nasima Begum filed a case with Jhikargachha Police Station, reports UNB.
Officer-in-Charge Babulur Rahman Khan said police detained six people in connection with the incident and a drive is underway to arrest others involved.