Moscow, (IANS) : At least 10 people were killed and dozens of others injured in twin explosions that rocked a metro train in the Russian city of St. Petersburg on Monday, the media reported.

The explosions occurred as the train was travelling between the Tekhnologichesky Institut and Sennaya Ploshchad stations of the St. Petersburg Metro, the National Anti-Terrorism Committee said, adding that there was an unspecified number of fatalities.

The St. Petersburg Governor’s office said there were as many as 50 victims in the incident, including 10 fatalities.

There were blasts in two metro carriages at two stations, St Petersburg emergency services said.

RT Online quoted Transit Systems management as saying that evacuation of passengers was on after the explosions at the Sennaya Square station.

Russian President Vladimir Putin has pledged a thorough investigation. “The causes of this event have not been determined yet, so it’s too early to talk about (possible causes). The investigation will show. Certainly, we will consider all variants, common, criminal, first of all, of a terrorist nature,” he said.

The door of a train coach was blown off by the impact of the explosions.

The entire transit system has been shut down as bomb squads and rescuers are responding to the emergency.