Alwaght- Russian security forces detained a group of seven people suspected of planning terror attack on Saint Petersburg.
Russia's Federal Security Service (FSB) issued a statement on Friday, saying the detainees were suspected of plotting attacks on railway trains and public sites in Russia's second-largest city.
FSB did not identify the detainees but described them of being from Central Asian countries.
Some 15 people were killed in a blast on the St. Petersburg metro on April 3.
Akbarjon Jalilov, a 22-year-old Kyrgyz-born ethnic Uzbek man with Russian citizenship carried out the suicide attack. At the same day, a second, larger device was found and defused at another station.
Ten suspects from Central Asia were arrested in St. Petersburg and Moscow in connection with the attack shortly afterwards.
Russia was once a hotspot for terror attacks, but the country has experienced relatively few in recent years.
In December 2013, a suicide bombing at a train station in Volgograd killed at least 16 people. The following day, in the same city, a suicide bombing on a trolley bus killed 14 people.
In 2010, two female suicide bombers blew themselves up at two Moscow metro stations, killing 40. They were linked to the Chechen insurgency.
And in 2002, Chechen rebels killed 170 people in a theater hostage situation in the capital, Moscow.
