The Odessa branch of the SBU said in a statement several Ukranians and citizens of Middle Eastern countries had been detained for trying to traffic red mercury, which is used in nuclear weapons.

The suspects had obtained the mercury in Ukraine and had tried to take it out of the country in special containers, it said.

Several more arrests were expected, it said, without giving details.

On May 6 the SBU announced it had arrested several members of a criminal gang that was trying to illegally purchase two containers of radioactive Cesium-137 in Crimea for 120,000 dollars.

The authorities had followed the gang for six months and believed it wanted to purchase the containers to sell off to other clients, Interfax reported.

Cesium-137 is used in metallurgy and medicine. It can also be used for the construction of "dirty bombs" that emit low-level radiation.

WAR.WIRE