A radio-active cesium was found in a lead container Bulgarian police seized from a provender factory in Asenovgrad.

A can of cesium weighting 190 kilograms came to the factory from Ukraine, police said in a statement Monday.

So far it is not known how radio-active material came to Bulgaria and why it was housed in a provender factory.

Cesium is used for photo-cathodes production for photocells, and radionuclide Cesium-137 is used in radio-therapy.

Bulgarian police stated that they have arrested three persons under suspicion that they are the owners of the 40-centimeters radius lead container that was found in an industrial area of the Asenovgrad.