Unidentified miscreants hacked to death an activist of the Juba League, the youth front of the ruling Awami League, in the Ambagan area of Tiger-pass, in the port city early on Tuesday.
The deceased was identified as Hasan Murad, 31.
Abdur Rouf, assistant commissioner at the Panchlaish zone of the Chittagong Metropolitan Police, said the miscreants intercepted the motorbike of Murad at Ambagan while he was returning to his residence, and then attacked him.
The AC also said the critically injured Murad had been rushed to the Chittagong Medical College Hospital, where the on-duty doctors announced him dead around 12:15 am.
Noor Islam, assistant sub-inspector of Khulshi police station, said the killing was for factional feud.
One Riad was arrested in connection with the murder.
Police also seized a pistol and a revolver from his possession.
The process of filing a case was underway, said the ASI.