Alexander Bortnikov told a meeting of chief editors from leading Russian media outlets that, "The criminal activity of over 680 bandits and their accomplices has been stopped, 97 terrorist acts, of which 50 were planned to take place in public places, were prevented."
Bortnikov said about 900 people had been convicted of terrorist and extremist crimes, adding that "some 4,000 firearms, over 2 million pieces of ammunition, about 4,000 explosive devices and 8 tons of explosives had been seized."
The FSB director also said the internal security service was currently working in cooperation with 137 intelligence services in 77 countries.
"Official representatives of Russia's FSB are in 40 states," he said.
Bortnikov said the FSB had prevented around 55 billion rubles ($2 billion) worth of damage, adding that over 1,300 criminal cases had been launched involving corruption leading to more than 500 people being convicted.
The director said that the FSB had prevented some 48 officials and 101 agents employed by foreign intelligence services from operating in Russia.