A joint operation by the Kolkata Police Special Task Force (STF) with Asansol-Durgapur Police led to the busting of an illegal arms factory at Neamatpur in Kulti block in West Bardhaman District of West Bengal on May 29, reports The Times of India. Security Forces (SFs) recovered about 350 state-of-the art semi-finished 7mm pistols from the arms factory.