Reports now coming in, from The Guardian
St Petersburg metro rocked by explosion
An explosion has hit the St Petersburg metro, according to witness reports. The blast apparently occurred at the Sennaya Ploshchad station in the centre of Russia’s second biggest city.
Photographs from the scene showed a metro train in the station with one set of doors blown out, and a number of people on the ground with injuries. There was no immediate information about the number of casualties or what caused the explosion.
A live stream on the Russian website Life News said there had been either one or two explosions around 2.30pm local time. The video showed hundreds of people waiting outside the station entrance at street level, along with fire engines and police vehicles.
More details soon ...