The Mexican authorities have offered a two thousand, five hundred dollar reward for the return of a container of high level radioactive material that is thought to have fallen off the back of a lorry outside Mexico city. The National Commission for Nuclear Safety has also set up emergency phone lines and has issued a public safety warning about the metal box, which went missing eleven days ago. As Emma Paterson reports, this is just the latest in a series of similar accidents and has led to renewed criticism of the commission's handling of radioactive material.

The Mexican police and a team of scientists have spent several days hunting for the radioactive box, but without success. The container disappeared from the back of a truck travelling along the main highway between Mexico City and the nearby town of Puebla.

Local authorities believe the truck may have shed some of its load during the journey as its cargo hatch slipped open. So far, the search for the missing box has proved fruitless and the civil protection authority is now appealing for the public's help.

The metal box contains iridium, a radioactive material used for industrial x-rays. It's an extremely dangerous product, which, on contact with the skin, can rapidly destroy body cells and force the amputation of limbs.

National television stations have warned the public that tampering with the missing box could prove fatal. This is the second radioactive container that's gone missing this year, raising further questions about safety standards in Mexico.