A truck carrying "extremely dangerous" radioactive material was found Wednesday close to the place where it was stolen in Mexico, authorities said. The cargo was found about half a mile from the container.
The vehicle was transporting radiotherapy equipment containing the radioactive isotope cobalt-60 from a hospital to a waste storage center, the International Atomic Energy Agency said.
"At the time the truck was stolen, the source was properly shielded," the IAEA said in a statement. "However, the source could be extremely dangerous to a person if removed from the shielding, or if it was damaged."
The thieves likely opened the container not knowing what it was carrying and burned themselves, Juan Eibenschutz, general director of Mexico's National Commission of Nuclear Security and Safeguards, told NBC News. The thieves are likely either dead or dying following the incident, Eibenschutz added.
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Officials have closed off the area where the radioactive material was found. They are conducting tests to determine when it is safe to approach it.
The vehicle is a 2.5-ton Volkswagen truck with an integrated crane. It was stolen on Monday at a gas station in Tepojaco, near Mexico City.
Mexico's federal, state, and local authorities were involved in a widespread and coordinated hunt for the vehicle across several states, the CNSNS said.
U.S. officials say it's not at all clear why it had been stolen, adding that there was no indication it had been taken for any criminal or terrorist purpose.