In one of the biggest drug bust operations, the Directorate of Revenue Intelligence (DRI) has arrested a Chennai-based couple in Delhi in connection with the smuggling of 3,000 kg of heroin, reportedly worth Rs 21,000 crore, from Afghanistan. The drugs were seized by DRI officials from Mundra port in Gujarat on September 17, officials said. In other news, the Army is carrying out one of the biggest operations along the Line of Kashmir in North Kashmir after the infiltration attempt from the Pakistan side.