Russia's top domestic security agency said Monday it has thwarted suicide bombings in Moscow planned by the Islamic State group in Syria.
Four people have been arrested on suspicion of plotting attacks on Moscow transit system and shopping malls, the Federal Security Service, or FSB, said in a statement.
Those arrested included two would-be suicide bombers along with an Islamic State envoy and an expert in explosives. One of them is a Russian national and three others are from ex-Soviet Central Asia, the FSB said.
The agency released a video in which its agents inspect a house used by the group to make explosives while two suspects lie down on the floor in handcuffs. It didn't say when the arrests took place.
The FSB said the attacks were planned by two senior IS militants who fight with IS. The agency didn't give their nationalities, but their names given by the FSB appear to indicate they hail from the former Soviet Union.
In May, the FSB arrested another group of suspected IS members in May who were also accused of plotting terror attacks in the capital.
The arrests follow a suicide bombing in St. Petersburg's subway that left 16 dead and wounded more than 50 in April.
President Vladimir Putin said in April that some 9,000 militants, about half of them from Russia and the rest from ex-Soviet Central Asian nations, have joined the Islamic State in Syria.
He emphasized that a key goal for the Russian military operation in Syria is to crush them there and prevent them from coming back home.