A truck carrying radioactive material was missing Monday after being stolen in Mexico, the country's interior ministry said.
Five Mexican states were on alert after the theft, which was reported Saturday by a company in Queretaro.
The National Coordination of Civil Protection said a 2006 red Chevrolet Silverado pickup transporting radioactive iridium-192, used in radiography, was stolen in San Juan del Rio at about 6 a.m. local time (7 a.m. ET).
In a statement it said the material, which was being transported in a bright yellow container, "can be dangerous to people if not handled in safe conditions or if handled without the right protection."
"It can cause permanent or grave wounds to a person who handles it or is in touch with it during a brief period (between minutes and hours)," the statement said. "If the material is not found in its container it represents an important risk to health. The material is nevertheless not dangerous if it is still in its packaging."
In addition to Queretaro, the states of Hidalgo, Guanajuato, San Luis Potosi and Michoacan were put on alert.
In April 2015, a container carrying iridium-192 was stolen and recovered a week later in southeastern Mexico, the fourth such theft since 2013, according to Agence France-Presse (AFP).