The deceased was identified as Zakir Hossain, 48, son of Latif Hawlader of Morrelganj upazila in Bagerhat.
Locals said some members of a local teenage gang attacked and stabbed Zakir in front of the hostel of City College around 10:30pom, leaving him injured.
He was rushed to Khulna Medical College Hospital where doctors declared him dead.
Zakir was a dealer of mosquito coils and had returned to Bangladesh after spending several years abroad.
Officer-in-Charge of Khulna Sadar Police Station Haludar Sanowar Hossain Masum said police are investigating the motive behind the killing and working at the scene, reports UNB.