The Mexican authorities have issued an alert on Monday after a container of radioactive material was reported stolen along with a car in central Mexico on Saturday. Mexico’s National Commission on Nuclear Security and Safety said that the device, which is used in industrial radiography, was being transported in a red Chevrolet pick-up and was stolen from the municipality of San Juan del Rio.

The ministry said that the material, Iridium 192, is not dangerous if kept within its covering. If found, however, the container should be confined within a protective perimeter of 30 metres.

“It was classed as a Category 2 radioactive source,” the Reuters quoted a spokesman for the International Atomic Energy Agency (IAEA), the U.N. nuclear watchdog based in Vienna, as saying.

The classification of the material means that it could be fatal to anyone exposed to its radiation for a period of hours to days.

The nuclear commission, however, could not ascertain whether the thieves intended to steal the container with the radioactive material or simply made off with the vehicle, not knowing what else was in it. It was made aware of the theft on Sunday, following which it issued an alert in six Mexican states and the Federal Highway Police, to keep a watch for the Chevrolet Silverado truck. The truck and the material both belonged to Central Industrial Maintenance, the CNN reported.

An industrial radiography device uses radioactive isotope Iridium 192 to radiate gamma radiation for testing pipelines. The gamma rays can be fatal at a closer range.

IAEA has offered to help the Mexican authorities in their search. However, no assistance was sought by Mexico. In 2013 and 2015, there were reports of similar radioactive material being stolen in Mexico.

Earlier this year, a similar device also went missing in Iraq, which created concerns that it might have been stolen by terrorists for making “dirty bombs.” However, it was later found undamaged near a police station.