More than 50 instances of violations of airspace over crucial public facilities by drones have been registered in Russia since 2017, the chief of the CIS Anti-Terrorist Center, Andrei Novikov, Eurasia Diary reports citing Tass News.

"Experts identified a certain growth in the number of legal violations involving unmanned aerial vehicles (UAVs) in Russia. According to some estimates, more than 50 instances of violations of air space over important public facilities by drones have been registered since 2017," Novikov said.

Ways of resistance to the use of drones for terrorist purposes are of great interest to all special services. Currently great threats are posed by the unauthorized use of drones during mass events, where they can be used as means of delivering explosives or poisonous substances for terrorist attacks and also for spotting weaknesses in security systems.

"Equipping ordinary drones with certain gadgets turns them into reconnaissance aircraft or mini-bombers," Novikov explained.

Specialists say Russia these days has about 60,000 legal quadcopters registered in the names of amateur owners and about 3,000 drones in the corporate segment. The drones have a mass ranging 250 grams to 30 kilograms. In the United States the commercial sector alone uses no fewer than 1.5 million drones.