At least 10 people were killed in explosions in two train carriages at metro stations in St. Petersburg this Monday.
Fifty people have been reported injured by the blasts in St Petersburg’s metro system on Monday, according to Andrey Kibitov, the head of the city governor’s press service .
President Vladimir Putin, who was in St. Petersburg for a meeting with Belarussian leader Alexander Lukashenko, said the cause of the blasts was not yet clear and efforts were underway to find out. He said he was considering all possibilities including terrorism.
Authorities have closed all St. Petersburg metro stations. The Moscow metro said it was taking additional security measures in case of another attack there.
Russia has been the target of attacks by Chechen militants in past years. Chechen rebel leaders have frequently threatened further attacks.