The security service of Russia FSB announced today that it had arrested five people who tried to buy one kilogram of cesium-137of radioactive material, for 3.5 million dollars on behalf of a Ukrainian citizen, the TASS agency reported.

The FSB claimed that those arrested would transport the cesium-137 out of Russia to be used in a staged incident with alleged weapons of mass destruction, aimed at discrediting Moscow.

The five arrested have already confessed to their actions, the same source added, without giving further details.

The Ukrainian president Volodymyr Zelensky said on Thursday that Ukrainian spies had received information that Russia was considering launching a “terrorist” attack on the Russian-held Zaporizhia nuclear plant in southern Ukraine that would involve a radioactive leak.

Moscow called Zelensky’s statements “lies” and accused Kiev of planning to seize the nuclear plant and bombing its facilities, including nuclear fuel storage facilities. He has also accused Ukraine of planning a “dirty bomb” attack on Russia, which Kiev has denied.