At least 10 people have been killed in explosions at underground stations in St Petersburg, Russian media report.
The Tass and Interfax 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.
President Vladimir Putin, who is in the city, said all causes, including terrorism, were being investigated.
Interfax reported that at least 20 people had been injured, and that one of the blasts involved a device filled with shrapnel.
Tekhnologichesky Institut serves metro lines one and two, with the first hall opening in 1955, followed by the second in 1961.
Sennaya Ploschad – the next station along metro line two – opened two years later, in 1963.
Looks like Putin should have outlawed them pressure cookers when he had the chance. Sadly, it is now too late.
The Tekhnologichesky Institut Station is named after the famed Russian scientist Igor Tekhnologichesky who, coincidentally, invented the Russian version of the pressure cooker.
Only Igor named it the Multi Directional Sonic Shrapnel Extruder and Consumable Heating Device.
Saw a virtual plethora of articles this morning on this story.
Very scary… apparently. 🙄