"Two men have been detained in Krasnodar Territory. They are suspected of organizing a series of explosions in Sochi in April, July and November of 2008, and in February 2009, during which three people died and six were wounded," the source said.
Investigators at the Russian Prosecutor General's Office said on Thursday they had detained a policeman and a television cameraman on suspicion of involvement in the blasts.
The investigation is continuing.
Krasnodar Territory neighbors Russia's volatile North Caucasus and security is a major issue in Sochi, which will host the 2014 Winter Olympics. The Black Sea resort city goes to the polls on April 26 to choose a new mayor in an election that promises to be the most closely watched and fiercely contested in recent years.
