Several killed after blast on St Petersburg underground

At least 10 people have been killed in a blast on Monday at a metro station in the Russian city of St Petersburg, local media have reported.

At least 20 others were wounded in the explosion at the Sennaya Ploshchad station, according to Reuters.

Pictures screened on national television showed the door of a train carriage blown out, as bloodied bodies lay strewn on a station platform.

Above ground, emergency services vehicles rushed to the scene at the Technological Institute metro station, a key transport hub in the city centre.

The blast occurred at 2:40pm local time (1140 GMT) in a train carriage between the stations Technological Institute and Sennaya (Square), which are next to each other.

The spokesman for Russia's national anti-terrorism committee (NAK), Andrei Przhezdomsky confirmed that security services had found a device at the Vosstaniya Square metro station which didn't explode and "neutralised" it.

The metro network announced it was shutting down entirely after evacuating all passengers and Russia's Investigative Committee also began a probe into the blast.

The Moscow metro also tweeted that it was "taking additional security measures" as required by law in such situations.

NAK said in a statement carried by Russian news agencies that security was being stepped up at transportation hubs and crowded places across the country.

As of yet, no group has come forward to claim the attack, however CCTV images showing the alleged assailant have appeared in Russian news outlets.

The station is a busy hub of the underground network in the centre of Russia's second largest city.

Earlier reports suggested that there were two explosions, however it was later confirmed that there was only one blast that took palce on a train between two stations. 

Russian President Vladimir Putin, who was in St Petersburg early on Monday, offered "condolences" to those hurt in the blast, adding that authorities are considering all possible causes, including terrorism.