Russia's Federal Security Service (FSB) says its officers in the southwestern city of Volgograd have detained a teenager who is suspected of plotting a deadly school attack amid a rise in such cases across the country.

According to a statement by the FSB on June 15, the 15-year-old suspect was charged with illegally producing explosive devices. The statement also said it is possible that a charge of planning to murder two or more people may be added to the case.

According to the statement, investigators confiscated a handmade explosive device, Molotov-cocktails, components of explosive substances, and a bladed weapon.

Historically, attacks at schools in Russia and other former Soviet republics are uncommon. However, in recent years they have been on the rise.

The June 15 announcement came less than two months after a court in the Siberian city of Krasnoyarsk arrested a 14-year-old boy suspected a deadly school attack.

The suspect was charged with terrorism and planning a criminal act.

Earlier in February, FSB officers detained two teenagers in the city of Saratov in the Volga area on suspicion of plotting a deadly gun-and-bomb attack in a local school.

That same month, the FSB said that its officers had prevented a school attack in the city of Kerch in Russia-controlled Crimea, while a court in the far eastern city of Khabarovsk sentenced a teenager to eight years in prison after convicting him of planning a school shooting.

With reporting by Interfax and TASS