A device containing radioactive substances was stolen from a government research facility and authorities are working to track it down, Mexico's No. 2 official said.

"We have the report regarding the theft of this material and the alerts and protocol we follow in these cases have already been implemented," Government Secretary Miguel Angel Osorio Chong told reporters after speaking at a conference of state law enforcement chiefs and attorneys general.

Exposure to the cesium-37 and americium-beryllium inside the stolen piece of equipment is not likely to cause permanent injury, the central government said in an alert distributed to authorities in Mexico City and the states of Mexico, Morelos, Puebla, Tlaxcala, Guerrero, Michoacan, Guanajuato, Queretaro, Hidalgo, Oaxaca and Veracruz.

A group of armed men grabbed the device Sunday night during an assault on a National Construction Laboratory warehouse in Tultitlan, Mexico state.

Handling the material without proper safeguards or spending an extended period in close proximity to the radioactive substances could result in temporary health problems, according to the bulletin.

Last December, armed robbers stole a truck transporting cobalt-60 from a hospital in the northwestern border city of Tijuana to a radioactive waste storage center.

Mexican authorities located the truck and the radioactive material days later and arrested six people in connection with the heist.

None the suspects suffered any effects of radiation exposure and officials found no trace of contamination at the site where the truck was recovered. EFE