At least 10 people are reported killed and 50 injured in an underground explosion in a station in the city of St Petersburg, Russian media report. Reports say there were two separate blasts in two carriages. People were evacuated from the stations immediately.
The Tass and Interfax agencies reported a blast at the Sennaya Ploshchad metro station, which left a number of victims.
Images posted on social media showed a train carriage with its doors blown out and damage inside. All metro stations in St Petersburg have been closed, Interfax reported, citing metro staff. The blast happened as Russian President Vladimir Putin was meeting with Belarussian leader Alexander Lukashenko in the city. President Vladimir Putin said he could not rule out the blast being a terrorist attack and expressed his condolences to the families of the victims and those injured. Russian anti-terrorist units neutralised an improvised explosive device (IED).