Radioactive material that was stolen in Cardenas, Tabasco on April 13 was recovered on Wednesday.

The small container of deadly material had been abandoned under a pedestrian bridge.

This is the fourth incident of pilfered radioactive material occurring in Mexico since 2013.

The theft of the toolbox-sized container, which was carrying an Iridium-192 capsule, set off an alert in five southern and eastern states, as well as sparking the activation of federal forces.

As reported by Yahoo, officials believe that, as with the previous three cases, the thieves were in fact unaware that they had actually stolen a radioactive item and were more interested in stealing other items.

The authorities stated that after someone had contacted the state police via phone, the capsule was recovered under a bridge on a road linking Cardenas with Tabasco's capital Villahermosa.

Around 100 security forces were sent out for the recovery.

According to Christian Romero, the deputy director for radiological emergencies at the national nuclear commission, "There are no signs that the container was opened."

Mexican officials have informed the public that, so long as the material was kept under seal, the capsule posed no threat. They did however advise everyone to stay away from the material if it was found. Luis Felipe Puente, the National Civil Protection Coordinator, revealed that the Iridium-192 was now "under guard" after Mexico’s nuclear safety commission confirmed that the material was indeed recovered.

Iridium-192, which is used for industrial radiography to check welding seams, can cause burns, radiation sickness, and permanent damage to a person who comes in contact with it. If a person is exposed to it for hours or days Iridium-192 can cause death.

As reported by the BBC, when authorities in Mexico previously recovered dangerous radioactive material in 2013 the police believed that the thieves had planned to just sell the device for scrap metal.