In a major breakthrough amidst the ongoing drive to making Punjab a safe and secure state as per directions of Chief Minister Bhagwant Singh Mann, Punjab Police’s Anti-Gangster Task Force (AGTF) in a joint operation with Himachal Pradesh Police has arrested four associates of Harpreet Happo Gang for their involvement in the Gym Trainer murder case, said Director General of Police (DGP) Gaurav Yadav here on Thursday.