Authorities in Moscow say they have detained a suspected member of the Islamic State terrorist group who previously fought in Syria, Interfax reported Wednesday, citing an unidentified source in the security services.
The suspect was detained several days ago for questioning over his activities in Syria from the end of last year to early 2014, the source was cited as saying, adding that authorities believed he was fighting alongside the Islamic State during that time.
A criminal case has been opened against him on charges of participating in an illegal armed group, and he faces up to 10 years behind bars on the charges, the report said.
No further details were provided.
The news follows a video warning from members of the radical militant group to President Vladimir Putin on Sept. 3 in which they threatened to wreak havoc in Russia. They vowed to "free" the turbulent North Caucasus, which for years has battled a simmering Islamic insurgency of its own.
Russia's Federal Security Service has estimated that hundreds of Russian nationals, many from the North Caucasus, have gone to Syria to fight since the beginning of the conflict in 2011.
In late August, Foreign Ministry official Ilya Rogachyov warned that the Islamic State's radical ideology, based on a seventh-century form of Islam, could prove appealing to some groups in Russia.