A major defensive exercise has been taking place at the American airbase at Lakenheath in Suffolk

Gas masks and protective suits have been the order of the day as personnel dealt with simulated attacks on the base.

The exercise had been long planned, but was considered particularly timely as tension mounts in the Middle East.

Servicemen and women had to deal with a simulated mortar attack on the airbase, with smoke drifting across the runways.

Col Snider said the forces face real threats

Dozens of airmen, wearing protection suits, were evacuated from a command centre, as a disposal team located and defused an unexploded mortar bomb - just yards from an armed F15 aircraft.

Lieutenant Colonel Pete Whelan, of the 48th Fighter Wing, said these mock exercises were vital.

"This gives them the opportunity to practice these skills in a non-threatening environment before we have to forward deploy in a combat situation," he said.

The exercise shows that the threat of chemical and biological attack is taken very seriously.

Serviceman rush to get their equipment

Colonel John Snider, a wing vice-commander, said the 5,000 servicemen and women based at Lakenheath could be deployed anywhere around the world where this type of attack is possible.

"We had over 600 folk from Lakenheath down range in 18 countries over the summer in locations where there was a real threat of this kind of action," he said.

"They recognise this is the business we are in."