Mexican authorities have issued alerts over the apparent theft of radioactive material.

Officials have appealed to the people to stay alert and call police if they find the container for the radioactive material.

According to the BBC, the Mexican government enacted alerts on five states following the theft of a container carrying Iridium-192. The contained was taken along with various other items out a truck transporting it when it was stationed in a residential area.

The states put on alert are Campeche, Chiapas, Oaxaca and Veracruz as well as Tabasco, where it was stolen.

Luis Felipe Puente, head of Mexico’s civil protection agency, tweeted an image of the container, which looks like a toolbox. He also warned on Twitter that anyone who finds the container is to stay away from it and contact the authorities.

"Each time that one of these units have disappeared from the hands of companies in charge of them, we have recovered them with the help of the population," Puente said on television, according to the AFP. This is not the first time radioactive material has been stolen in Mexico.

The material is used for checking welding seams and was reported stolen by the company Garantia Radiografica e Ingenieria on Monday.

Christian Romero deputy director for radiological emergencies for Mexico's National Nuclear Security and Safety Commission said thieves do not know what they are stealing when they do it.

"As long as it remains inside the container, there is no risk at all to anybody," he added. But, if opened, the material can cause burns.

The last theft happened in July 2014 when thieves stole a truck carrying the same substance, Iridium-192, unknowingly, reported Reuters at the time. The thieves later dumped the truck with the material inside.