Russian security agents have detained a ninth person in connection with the St. Petersburg subway train bombing that killed 15 people and injured 45 on April 3.
A statement from the country's security service, the FSV, said the suspect, 27-year-old Abror Azimov, was detained on April 17 in the Moscow region's Odintsovo district "in the framework of the criminal case" over the suicide terrorist attack.
The FSB statement said Azimov was a "native of the Central Asia region" and allegedly had "trained the suicide attacker."
Akbarjon Jalilov, a 22-year-old Kyrgyz-born ethnic Uzbek man with Russian citizenship, has been identified by Russian authorities as the suicide bomber.
Law-enforcement officials have been trying to determine Jalilov’s motives, whether he had been radicalized by Islamic extremists, and whether anyone else assisted him in the planning of the bombing.
There has been no claim of responsibility for the attack.