"Two people were declared wanted on suspicion of preparing explosions: one of them is the person who placed the explosive device in subway car, another one left the bomb at Vosstaniya Square station," the source told.
He reminded that second explosive device disguised as fire extinguisher was defused.
Russian TV channel REN TV also published a photo of the person suspected in Saint Petersburg explosion.
Later Fontanka agency published a photo of the viable suspect. It was reported that the Criminal Investigative Service of St. Petersburg is looking for him after explosion in subway. Some say he entered the metro at Petrogradskaya station 20 minutes before the explosion occurred at Tekhnologichesky Institut station.
Interfax also informed referring to the sources that surveillance cameras captured the possible organizer of the explosions in Saint Petersburg.
As it was reported earlier, explosion occurred at Sennaya Square station in Saint Petersburg at 3:30 p.m. Death toll reaches 10 people, about 20 got injured. All stations in the city were closed after the incident.
Russian President Vladimir Putin discussed metro explosions with FSB leadership, saying that all versions are being considered at the moment.
Foreign Ministry of Ukraine is also trying to figure out whether there are Ukrainians among victims and injured in underground blasts in Saint Petersburg,