"We have been actively involved in the work since receiving the message on the act of terrorism. Colleagues from the FSB got in touch a couple of hours later," NSC Deputy Chairman Maj. Gen. Nurgaly Bilisbekov said.
Bilisbekov said the NSC, FSB and "the special services of neighboring states are looking into versions of the involvement of one Russian citizen and a native of Central Asia, not Kazakhstan."
An explosion on Monday afternoon between two central St. Petersburg metro stations killed at least 11 and wounded 45, according to Russia's National Anti-Terrorism Committee (NAK).
Russia's Investigative Committee has opened a criminal investigation into a suspected terrorist attack.
"Today we continue intensive exchange of information," Bilisbekov said, adding that more details on the perpetrators of the act would be provided to the press "in the next few hours."
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