At least ten people have been killed and 30 wounded after two explosions happened at Saint Petersburg metro station.
According to media reports several casualties have been reported at the Institute of Technology station and the Sennaya station of the Saint Petersburg metro. Security and medical personnel have been first responders to the scene of incidence.
All central Saint Petersburg metro stations have been closed and security is tight in other Russian cities including the capital, Moscow.
President Vladimir Putin has expressed condolences and said the state security services were looking into all motives including terror motives.