'Nawsher' died at Khulna Medical College Hospital around 12:30am Friday, said Fultala police Inspector Sanwar Hossain.
Alauddin Mithu, BNP's organising secretary in Khulna, was attacked while he was sitting with his associates outside his office at Fultala Bazar at 10pm Thursday, Inspector Sanwar said quoting witnesses.
"The miscreants came on two motorcycles and fled the scene immediately after opening fire. Mithu died on the spot while his associate Nawsher suffered injury," he said.
Police have detained 22-year-old Imrul Sheikh although no case has been filed over the incident.