The Federal Security Service (FSB) on Wednesday detained four members of a "sleeper cell" of the terrorist group Daesh* in the Kaluga Region.
"Four members of a so-called 'sleeper cell' of Islamists, residents of the Yamalo-Nenets Autonomous District led by an emissary who was trained in Syria and arrived from the conflict zone for organizing terrorist activities, were detained in the Kaluga region on March 14," the FSB informed.
The identity of the detainees was not disclosed due to the ongoing investigation. There is no information as to whether the emissary himself was detained. The FSB stresses that the investigation is still underway.
On December 27, an explosion, which was declared a terrorist attack by Vladimir Putin, occurred at a grocery store in St. Petersburg, leaving at least 13 injured.
In October, Federal Security Service has detained four people related to Daesh, who are suspected of planning terrorist attacks in crowded places.
*Daesh (also known as ISIS/ISIL/IS) is a terrorist group banned in Russia