TBILISI (Reuters) - Georgia’s security service said on Monday it had detained six Georgian and Armenian citizens who were trying to sell $200 million worth of uranium-238.

Georgia’s security service did not say whether the group had a buyer for the uranium. Nor did it say where the group had acquired it.

However, Georgia is a former member of the Soviet Union, and world leaders have been concerned about the security of Soviet nuclear weapons since it broke up in 1991.

“Officers of Georgia’s State Security Service detained three citizens of Armenia and three citizens of Georgia,” security service investigator Savle Motiashvili told a briefing.

“The members of the group were planning to sell the nuclear material, uranium-238, for $200 million when they were detained,” he told a news briefing.

Motiashvili added that a prefabricated container meant for transporting the Uranium-238 was found at one of the detainee’s apartment.

“Given the gamma ray emission, the identity of the source and radiological expertise report, the seized substance is dangerous for life and health,” he said.

A Tbilisi city court sentenced members of the group to pre-trial detention. They face five to 10 years in prison if proved guilty.

Georgia’s security service has stopped several attempts to sell uranium or other radioactive materials. In 2006, a resident of Russia’s North Ossetia region was arrested for trying to sell weapons-grade uranium for $1 million to agents he thought were radical Islamists. He was sentenced to 8 1/2 years in prison.