A Trinamool Congress (TMC) activist was shot dead at Bhangar in south 24 Parganas district ahead of the panchayat polls in the district on July 19.
The CPI(M) district committee member Sattar Mollah and seven other party activists were later arrested in connection with the murder, police said.
Nazrul Mollah, a panchayat poll booth committee member of TMC, was called out from his residence by some people and shot at from point blank range, police said, adding he died on the spot.
The Trinamool alleged Mollah was an active party worker and he was killed to scare away the party supporters and voters in the area.
The CPI(M) said its activists were framed and the murder was the fallout of TMC's internal feud.
The third phase panchayat polls in West Bengal will take place on July 19.
