MOSCOW, June 23. /TASS/. Moscow’s Khoroshevsky Court has ruled to arrest four people in a case of smuggling a radioactive substance called caesium-137, a court spokeswoman told TASS.

"The court has granted the motion of the investigation," she said.

The people identified as Sakhalov, Abdulayev, Shamilov and Takhmazov have been taken into custody until August 21, the spokeswoman said. They are suspected of committing a crime provided for by Russian Criminal Code article on smuggling of radioactive substances, she said.

Russia’s Federal Security Service, also known as the FSB, said earlier on Friday that it had apprehended five Russian citizens who attempted to buy 1 kg of caesium-137 for $3.5 million, in coordination with a Ukrainian national. The plan was to take the substance out of Russia and use it in the area of the special military operation, then accuse Russia of deploying a weapon of mass destruction, the FSB said.