Officials were engaged Thursday in the delicate task of recovering a stolen shipment of highly radioactive cobalt-60 abandoned in a rural field in central Mexico state.

The material, which the International Atomic Energy Agency called “extremely dangerous,” was found removed from its protective container. The pellets did not appear to be been damaged or broken up and there was no sign of contamination to the area, the agency said Thursday, quoting Mexican nuclear safety officials.

Juan Eibenschutz, director general of the National Commission of Nuclear Safety and Safeguards, said it could take at least two days to safely get the material into a secure container and transport it to a waste site.

“It’s a very delicate operation,” Eibenschutz said. “What’s important is that the material has been located and the place is being watched to guarantee no one gets close.”

The missing shipment of radioactive cobalt-60 was found Wednesday near where the stolen truck transporting the material was abandoned in central Mexico. The atomic energy agency said it has an activity of 3,000 curries, or Category 1, meaning “it would probably be fatal to be close to this amount of unshielded radioactive material for a period in the range of a few minutes to an hour.”

Hospitals were on alert for people with radiation exposure, though none had been reported so far. Commission physicist Mardonio Jimenez said it was the first time cobalt-60 had been stolen and extracted from its container. The only threat was to whoever opened the box and later discarded the pellets of high-intensity radioactive material that was being transported to a waste site. It had been used in medical equipment for radiation therapy.

“The person or people who this took out are in very great risk of dying,” Jimenez said, adding that the normal survival rate would be between one and three days but added those who exposed themselves to the pellets could not contaminate others.

A family that found the container that had been used for the radioactive material was under medical observation, he added.

“It’s a family that found the container and carried it back to their house,” Jimenez told Milenio television. “For the sole fact that they were a certain distance from the source, we are keeping this family under medical observation … to determine how much they were affected by the radiation.”

The cobalt-60 that was missing for nearly two days was left in a rural area about a kilometer (a half a mile) from Hueypoxtla, a farm town of about 4,000 people. Officials said it posed no threat to the residents and there was no evacuation. Federal police and military units on the scene threw up an armed cordon about 500 meters (yards) around the site.

But townspeople complained they hadn’t been given any information about what had been found in the nearby field.

“We don’t know anything,” resident Jose Antonio Rosales told Milenio Television. “We don’t know if it’s good, if it’s bad. The authorities haven’t told us anything.”

The cargo truck hauling the cobalt-60 was stolen from a gas station early Monday in the neighboring state of Hidalgo, about 40 kilometers (24 miles) from where the material was recovered, Jimenez said. Authorities had put out an alert in six central states and the capital by Monday night looking for it.

The material had been removed from obsolete radiation therapy equipment at a hospital in the northern city of Tijuana and was being transported to nuclear waste facility in the state of Mexico, which borders Mexico City.

Eibenschutz said there was nothing to indicate the thieves were after the cobalt or in any way intended for an act of terrorism, The thieves most likely wanted the white 2007 Volkswagen cargo vehicle with a moveable platform and crane , he said.

According to authorities, a truck marked “Transportes Ortiz” left Tijuana on Nov. 28 and was headed to the storage facility when the driver stopped to rest at a gas station in Tepojaco, in Hidalgo state north of Mexico City.

The driver told authorities he was sleeping in the truck when two men with a gun approached him. They made him get out, tied his hands and feet and left him in a vacant lot nearby.

Eibenschutz said the transport company did not follow proper procedures and should have had GPS and security with the truck.

“The driver also lacked common sense because he decided to park along a highway so he could sleep,” he said.

The company that owns the truck couldn’t immediately be located for comment. One Mexico City company called “Transportes Ortiz” said the truck was not theirs and they had nothing to do with the incident.

(AP)