"The FSB in the city of Kerch of the Republic of Crimea prevented the preparation of terrorist acts in two educational institutions by residents of Kerch in 2003 and 2004," the statement said.
According to the agency, the detainees are followers of 18-year-old Vladislav Roslyakov, who was involved in the killing of 21 people at the Kerch Polytechnic College in October 2018.
Homemade explosive devices with explosive elements, as well as components for the manufacture of explosives, were seized from detainees at the residential addresses.
“Tests of test explosive devices were conducted on pets,” added the FSB.
On October 17, 2018, a student, Vladislav Roslyakov, fired and exploded in a Kerch college, killing 21 people.