The FSB said the men, citizens of an unspecified Central Asian country born in 1991 and 1987, were killed after they refused to surrender and fired at officers who confronted them on April 19, Russian news agencies reported.
The FSB said the suspects 'were linked to recruiters for international terrorist groups, had shown interest in...the preparation of improvised explosive devices, and had expressed readiness to carry out terrorist acts on Russian territory,' state-run TASS reported.
The veracity of the reports cold not be independently confirmed.
The shoot-out came 16 days after a suicide bombing authorities blame on an ethnic Uzbek, Kyrgyzstan-born Russian citizen that killed 15 people on a subway train in St. Petersburg.
Nine people have been arrested in connection with that attack.
Based on reporting by RIA, TASS, and Interfax