Superintendent of Police Prabin Kumar Tripathy said the incident took place at Raideghi when the TMC supporters were holding a meeting.
Some miscreants opened fired on the TMC supporters in which four were killed and three others injured.
The miscreants fled after the attack.
The dead have been indentified as Hasan Gaji, Hafisul Gaji, Atiar Mollah and Sabu Mollah.
The injured who are Ayub Mollah, Kutub Mollah and Krishna Charan Mistri and have been admitted to the Raideghi hospital.