The Federal Security Service (FSB) said two suspects had been detained on suspicion of being involved in the plan to assassinate Matviyenko, who is a close ally of President Vladimir Putin.
The FSB said the suspects, both Russian citizens, were detained on May 16 and found to be in possession of two hand grenades and more than 500 grams of plastic explosives.
The 58-year-old Matviyenko, who is considered one of the most influential women in Russian politics, told reporters she feels calm and has no plans to increase security measures.
(compiled from agency reports)
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