Drug police in the Moscow region seized some 50 kilograms of heroin, the regional department of the Federal Service for Control of Drugs and Psychotropic Substances Circulation told Itar-Tass. "In the course of a special operation, police stopped the activity of a criminal group, seizing a particularly large batch of heroin weighing some 50 kilograms," drug police said. The operation was carried out in the Shchelkovsky district on August 11-12, Itar-Tass reported. The investigation continues. Law-enforcement bodies are trying to establish the whereabouts of the supply source and the trafficking channels. A search for the smugglers of narcotics is underway.