According to him, the law enforcement bodies conducted a number of operational searching measures aimed at finding out and checking terrorist acts.
The source said that the law enforcers obtained information about several explosions with the use of cars being prepared in Moscow.
During the investigation on Friday night, militia managed to find out and render harmless a car, already prepared to be blasted, which was parked by an apartment building in the centre of Moscow.
Two other cars which the criminals planned to fill with explosives and to explode was also found, the source in the Moscow law enforcement bodies reported.
He also said that presently the Russian Interior Ministry's services were establishing the plotters.
Earlier on Saturday, the NTV channel reported that two cars with explosives were found in the centre of Moscow.
According to the NTV, a car with trotyl charges was found in Granatny Pereulok. The militia cordoned the place. FSB explosion specialists rendered the charge harmless with the help of a water gun.
Another similarly stuffed car was found at a doorway of an apartment building in Bogoslovsky Pereulok, the NTV channel said. Residents were evacuated for the sake of safety. The explosives were neutralised, by shelling them from a water gun.