ST. PETERSBURG: Russia's National Anti-Terrorism Committee says it has found and deactivated a bomb at another St. Petersburg subway station.
German Foreign Minister Sigmar Gabriel says he learned of the deadly explosion in St. Petersburg "with deep sorrow."
Although the cause of the explosion has not been confirmed, Gabriel says it appeared to be "a perfidious attack against innocent people."
Russian President Vladimir Putin says investigators were looking into whether the St. Petersburg subway explosion was a terror attack or if there might have been some other cause.
He says: "Law enforcement agencies and intelligence services are doing their best to establish the cause and give a full picture of what happened."
Putin happened to in St. Petersburg for a meeting with Belarusian leader Alexander Lukashenko.
Russia's National Anti-Terrorism Committee has announced that security will be tightened at all critical transport facilities following St. Petersburg blast.