Custom officers in Moscow's Sheremetyevo airport on Friday seized radioactive materials from the luggage of a passenger bound for Teheran, the Russian Federal Customs Service said.

The customs service said in a statement that high radioactivity was detected while checking luggage for the flight to Teheran. During a hand search, officers found 18 metal rods emitting radiation 20 times higher than natural levels.

The rods were made of Natrium-22, which can made only in magnetic-resonance accelerators.

A criminal case was opened. The passenger's identity and citizenship were not disclosed.

Natrium-22 could be used in medical industry.

Russia and Iran signed an agreement on the supply of medical-purposed isotopes of molybdenum-99 and iodine-131.