Explosion at two underground stations in St Petersburg are understood to have killed at least ten people, with around 50 people injured.
The BBC says The Tass and Interfax agencies are reporting that the blast happened at “the Sennaya Ploshchad and nearby Institute of Technology stations in the centre of the city”.
The cause of the explosions is not yet known, although The Telegraph is reporting the possibility of the use of “shrapnel-filled devices”, and has published several images showing blown out metro train doors.
All metro stations in the city are understood to have been closed following the explosions.
Russian President Vladimir Putin is reported to be in the city.
Business Traveller will update this article as it gets more information.