"Three citizens of Ukraine were detained in Melitopol on their way to the place of laying an explosive device in one of the city's markets," the FSB CSO said in a statement.
It is noted that two of them, previously convicted of serious crimes on the territory of Ukraine, confessed.
According to them, they acted on the instructions of the Ukrainian special services "in order to intimidate the civilian population of the Zaporozhye region."
Components of an improvised explosive device based on plastite and electric detonators were found in the car of the detainees, two pistols with ammunition, a grenade with a fuse were found in the apartments.
The defendants were taken to Moscow.
A criminal case has been initiated.
At the end of November, the FSB of Russia stopped an attempt of sabotage at military and energy facilities in the Voronezh region by supporters of Ukrainian nationalists.
The leader of the group and his accomplices were killed during an attempt to detain, none of the civilians and security forces were injured.