Kolkata: Four people have been arrested in connection with the murder of TMC leader Rajjak Khan in Bhangar in West Bengal's South 24 Parganas district, police said on Monday. Khan (38), a close aide of TMC leader and Canning Purba MLA Saokat Molla, was shot dead while he was returning home after attending a party meeting in Chaltaberia area on Thursday night. He was the president of TMC's Chaltaberia unit. A person with alleged links to the TMC, Mofazzel Molla, was arrested on Sunday in connection with the killing of Khan, a police officer said. Upon interrogation, he named three others, identified as Azharuddin Molla, Jahan Ali Khan and Raju Molla, who were arrested in raids conducted in Bijayganj Bazar and Chak Maricha areas late on Sunday, an officer of Uttar Kashipur police station said.