At least 10 people are feared dead and 50 others injured after explosions rocked a metro station in Russia's second city of Saint Petersburg, Al Arabiya News Channel's correspondent reported.
There were blasts in two train carriages at two metro stations, St Petersburg emergency services said.
News agency Interfax cited a source as saying at least one of the blasts involved a device filled with shrapnel. The agency also said that 50 people had been injured.
Russian President Vladimir Putin says his government is “considering all causes, including terrorism”.