Police in Karachi on Sunday night busted a 'unique' gang of four robbers that committed criminal activities for four years under 'standard operating procedures'.

The gang members, identified as Abdul Sattar, Ishaq, Tabir, and Nadeem, are believed to have been involved in a number of robberies in and around marketplaces in Gulshan-i-Iqbal, Tariq Road, and Paposh Nagar.

Special Services Unit (SSU) Senior Superintendent Tariq Dhanjo said, "The group is unique as it operates under SOPs that the members had set for themselves."

With the help of Ishaq, who was a jeweller by profession, the robbers would identify and target women who were wearing jewellery made of real gold and other valuable materials.

The gang would wrap up their criminal activities by 4pm and did not operate after those hours, police said. The robbers also considered Thursdays and Fridays holidays and would not carry out criminal activities on those days, police added.