The government has unveiled its plans for mass decontamination in the event of a chemical or nuclear attack by terrorists.

A 39-page document from the Home Office details proposals to cover the reaction to a "dirty bomb" and other types of chemical, biological, radiological or nuclear attack.

John Denham, the home office minister, said: "This guidance does not signal a new threat to the UK. If a specific credible threat becomes apparent, the government and the appropriate authorities will, without hesitation, inform the public of what action to take."