Members of our Armed Forces regularly visit the well guarded Porton Down establishment.

There, in a special train-ing laboratory, they are taught how to operate state-of-the-art technology which is being developed to give protection against an attack by biological weapons.

The Prototype Biological Detection System is an extremely sensitive piece of equipment which gives a rapid warning if troops come under attack.

Its sensors can pick up signs of highly infectious bacteria, viruses and other toxins.

Most biological weapons would be sprayed into the air in the form of an aerosol cloud from a plane, ship or vehicle, and the detection equipment has been built to suck in air samples, analyse them rapidly and then warn of any dangers.

Scientist Stuart Reeman who is working on the project said it was developed in response to urgent military demands following the Gulf War and can be used both on land and at sea.

"The kit is simple to use and is taken out into the field in special trucks, and so far tests have proved to be very successful," he said.

"It is an early warning system so that precaution-ary steps can be taken to protect soldiers and sailors."