Six specialist units cover Norfolk, Suffolk, and Cambridgeshire

The six vehicles - which cost �160,000 in total - hold gear provided by the government, including portable showers to wash patients before treatment.

And there are helmeted decontamination suits for 200 staff.

Brian Ablett, an ambulance technician, told BBC Look East: "The suits are hot inside, but you've got cool air blowing over the top of your head, and they are quite easy to work in.

"They're reasonably comfortable, anyway."

Emergency workers have already had practice using the items during a terrorist alert exercise in Thetford, Norfolk, involving the military, emergency services and local councils.

The shower unit resembles a children's bouncy castle

Roy Wallis, with the ambulance service, said: "Even prior to September 11, the ambulances were given the remit by the government to decontaminate injured casualties.

"That incident made everyone realise we need to have more equipment, because the number of casualties could be higher.

"Here we can deal with up to 600 casualties with three units."

During the Iraq war, when the threat of a terror-related chemical or biological attack was at its height, the ambulance service was on a high alert.

The service covers the counties of Suffolk, Cambridgeshire and Norfolk.