Venezuelan officials are conducting an urgent national search for a container with highly radioactive material that was stolen Sunday night.

The container of Iridium-192, was being carried in a light truck in the Yaracuy state when the truck was stolen.

Government officials have gone on Venezuelan television and radio, pleading with the thieves to return the container which is about the size of a lunch box because the material inside is potentially lethal.

They also said they are working on the assumption that the target of the theft was the truck, not its cargo, and that the thieves have no idea how dangerous Iridium-192 is.

Iridium-192 is used to treat certain cancers and in industrial gauges that inspect welding seams.

According to the U.S. Centers for Disease Control, it can cause burns, acute radiation sickness, an increased risk for cancer, and even death.

Some information for this report provided by Reuters.