The FSB security service, the successor to the KGB, said it had detained 10 people originating from Central Asia who were "planning to commit a series of high-profile acts of sabotage and terror in Moscow and Saint Petersburg;" AFP reported.
It said the suspects, detained in an operation in conjunction with the ex-Soviet Central Asian states of Tajikistan and Kyrgyzstan, had testified to contacts with IS (Daesh/ISIL/ISIS) leaders.
It said the group were suspected of plotting to murder civilians in busy public places using automatic weapons and powerful homemade explosive devices.
During raids on Saturday, the FSB said it confiscated four homemade bombs as well as trigger devices, guns, ammunition and communications equipment.
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