MEXICO CITY (AFP) - A toolbox-sized container with radioactive material that was stolen last week from a truck in southeastern Mexico was found Wednesday abandoned under a bridge, authorities said.
The April 13 theft of the box carrying Iridium-192 in Cardenas, Tabasco state, marked the fourth time since 2013 that robbers snatched radioactive material in Mexico.
"There are no signs that the container was opened," Christian Romero, deputy director for radiological emergencies at the national nuclear commission, told AFP.
Officials had stressed that the source posed no threat as long as it was kept under seal.
Officials believe that, like in the previous three cases, the thieves were unaware that they had stolen a radioactive source and were more interested in stealing the truck and other goods.
The material was recovered every time.
National civil protection coordinator Luis Felipe Puente said the Iridium-192 source was "under guard" after the National Nuclear Safety and Safeguards Commission confirmed that it was recovered.
Iridium-192 is used for industrial radiography to check welding seams.
The theft had prompted authorities to issue alerts and activate federal forces in five southern and eastern states.
It can cause burns, radiation sickness and permanent injury if a person comes in contact with it for minutes or hours. It is fatal if exposure lasts hours or days.
The theft was reported by the company Garantia Radiografica e Ingenieria.
The container was found near Tabasco's capital, Villahermosa, Romero said. The state government reported that it was abandoned under a bridge.
The night of the theft, the robbers had taken the container along with other objects inside the radiology company truck, which had been parked in the parking lot of a residential area in Cardenas.
The thieves left that vehicle alone and fled in another stolen truck.
PREVIOUS RADIOACTIVE ALERTS
Nuclear commission officials say companies are not required to have a security detail accompany material like Iridium-192. Security forces do escort more lethal material.
The biggest scare came in December 2013, when thieves took a truck containing a cancer-treating medical device with highly radioactive cobalt-60 near Mexico City.
Authorities arrested and hospitalised five suspects in that case after recovering the potentially lethal material, which the thieves intended to sell as scrap metal. They all survived.
That theft prompted the International Atomic Energy Agency to issue an alert for "extremely dangerous" material while US officials kept tabs on the situation.
More recently, in February, authorities recovered three stolen trucks in central Mexico transporting radioactive material for industrial use.
A similar incident took place in July 2014, also without causing harm to the population.