South African officials seized 2.2 pounds of uranium and 90 ecstasy tablets from two men allegedly trying to sell the items in the city of Durban, reports AFP.

Uranium serves as a crucial component in the construction of a “dirty bomb” also known as a radiological weapon. This type of explosive threatens with a blast as well as airborne radiation and contamination.

South African Nuclear Energy Corporation (NECSA) confirmed the substance was un-enriched uranium, and added that it most likely came from a country outside of Africa.

“Yes it is uranium and the tests suggest that it must have come from a country that is dealing with some uranium enrichment at the moment, very very unlikely (in) Africa,” NECSA spokesman Elliot Mulane told AFP.

The uranium is 0.38 per cent made up of the U-235 isotope and is well below the average 0.7 per cent of the U-235 found in natural uranium. Uranium would need to be at a 90% level in order to be considered weapons grade.

International atomic bodies were informed of the seizure and investigations will include countries involved with uranium enrichment like China, Iran, Japan, North Korea and the United States.

Mozambican Sasa Esmael Vulay, 23, and Sibusiso Solomon Mkhize, a 24-year-old South African, will remain in custody until December 3rd.

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