Efforts to prevent terrorist groups from obtaining materials that could be made into radioactive dirty bombs - or even crude nuclear explosives - are bound to fail, he said. And the result will be horror on an unprecedented scale.

"These materials are undoubtedly out there, and undoubtedly will end up in terrorists' hands, and undoubtedly will be used by terrorists some time soon," he declared. "We must plan for failure and prepare for absolute terror."

Dickinson is assistant chief constable with Lothian and Borders Police, and has responsibility through the Association of Chief Police Officers in Scotland for protecting Scotland from chemical and nuclear attacks . He has been closely involved in co-ordinating the country's counter-terrorism response.

He said: "An incident will continue for days and all the public will see is people dying without reason. What will we do when our children come home from school with blisters on their skin and their parents don't know what to do? "What happens if 10 deaths, 50 deaths, 100 deaths start occurring in an unconnected and random way all over the country? The public will be rightly and understandably terrified."

Casualties caused by radiation , which most people don't understand, would trigger widespread "panic and fear", said Dickinson. And the response of the emergency services "would be chaotic" because of a shortage of resources.

The police capability for dealing with the chemical, biological, radiological and nuclear threat - known as CBRN - needs to be increased, he argued. "I haven't got as many officers with protective equipment as I would like," he added. "We must prepare for the worst."

 Source : Sunday Herald