In one of the biggest jewellery thefts reported in the state in recent times, burglars broke into the Kisna Jewellers showroom in Katni’s Bargawan area, near LIC, and decamped with gold and diamond ornaments estimated to be worth Rs 12-15 crore. The thieves allegedly drilled through a nearly nine-inch-thick wall at the rear of the showroom and cleared out jewellery kept in display counters and safes.