St Petersburg metro explosions kill ten – media
At least 10 people have been killed in explosions at underground stations in St Petersburg, BBC reports citing the Russian media.
News agencies reported the blasts hit the Sennaya Ploschad and nearby Tekhnologichesky Institut stations in the centre of the city.
Images posted on social media showed a carriage in Sennaya station with its doors blown out with casualties nearby.
The Interfax and RIA news agencies reported that at least 50 people had been injured. Interfax said one of the blasts may have involved a device filled with shrapnel.
Russian President Vladimir Putin expressed his condolences to the victims adding all causes, including terrorism, were being investigated.
Moscow metro officials said they were introducing extra security measures as a result.