The Russian Federal Security Service (FSB) said Tuesday it has detained 18 suspected members of the Islamic State (IS) terrorist group in the Republic of Tatarstan for plotting terrorist attacks.

The FSB said in a statement that the detainees were suspected of forming a secret cell coordinated by the IS from abroad.

They intended to commit "headline-making" terrorist acts in Russia and join militants in Syria afterwards, according to the FSB.

They also allegedly recruited supporters from among radical youths.

The FSB said it had seized firearms and ammunition, extremist literature and IS symbols at the residences of the suspects.