MOSCOW, March 12. /TASS/. Russia’s Federal Security Service (FSB) apprehended 72 underground gunmakers in 28 Russian regions and shut down 37 workshops for weapons’ upgrade and ammunition production in a large-scale special operation, the FSB press office told TASS on Friday.

"The Federal Security Service in cooperation with the Interior Ministry, the Investigative Committee and the Russian Guard foiled the unlawful activity of 72 residents in 28 Russian regions complicit in recovering the combat properties of civilian guns at underground workshops and in their sale. The activity of 37 underground workshops for weapons’ upgrade and ammunition production was terminated," the press office said.

The FSB operatives seized 251 firearms, 80 kg of explosives, 21 artillery shells, nine hand grenades, over 25,000 cartridges of various caliber and 46 silencers, it added.

The firearms confiscated from the underground gunmakers included a ShKAS airborne machine-gun, three machine-guns, 26 assault rifles (AK-103, AKM, AK-74, AKS-74U), 24 submachine-guns, 130 pistols and revolvers, 67 rifles and carbines, the FSB press office specified.

The FSB carried out its special operation in Moscow, St. Petersburg, the Republics of Bashkortostan, Dagestan, Karelia, Crimea, Mordovia, North Ossetia and Khakassia, the Trans-Baikal, Krasnodar, Krasnoyarsk, Khabarovsk, Amur, Arkhangelsk, Astrakhan, Bryansk, Vladimir, Volgograd, Voronezh, Leningrad, Lipetsk, Rostov, Irkutsk, Kursk, Tver and Smolensk Regions and the Jewish Autonomous Region, it said.

"The work to uncover and foil the unlawful activity related to the illegal production, re-making and sale of weapons continues," the FSB press office said.