Shamli superintendent of police (SP) Pawan Kumar said a police team raided the house in Harmajpur village of Kandhla yesterday night and discovered the arms manufacturing unit.
The police team, led by Kandhla police station SHO Pankaj Verma, recovered parts of more than 400 pistols, arms manufacturing machines and accessories.
The SP said the police team first intercepted a car during regular checking and recovered 150 barrels of pistols. After quizzing the car occupants, police raided the house.