USAF Lakenheath airmen in 'legal high' ban in Norwich
Shops selling so-called legal highs have been asked not to supply the substances to US Air Force personnel based in Suffolk.
Two shops in Norwich said they complied with a request following purchases by airmen from RAF Lakenheath.
A temporary ban on shop visits was also issued.
The USAF said the order was "essential to maintain the health, safety, welfare, morale, security and good order and discipline of US personnel".
It added that it intended to "eliminate adverse conditions impacting US personnel caused by the sale of intoxicating substances".
'Pleaded with staff'
Head in the Clouds in Pottergate, which describes itself as Britain's oldest head shop, said it had agreed to not serve airmen following a recent visit.
According to the shop's owner, Martin Wyatt, "some of the US Air Force men were coming in to buy our intoxicants".
He agreed to put up a notice after the officers "came round with their tunics on and pleaded with us not to serve their staff".
The notice warns USAF personnel who "purchase intoxicating substances, other than alcohol and tobacco, are subject to adverse action under the uniform code of military justice".
Norfolk Trading Standards, which said that the ban is not enforceable, had accompanied the USAF on its visits.
In a statement, a spokesman for the 48th Fighter Wing said: "RAF Lakenheath has pursued an aggressive education program to ensure our airmen are aware of the dangers involved with using the mind-altering substances commonly referred to as Spice and Salvia.
"The steps taken to educate airmen on those dangers has proven to be highly successful as only two airmen out of more than 4,500 have been criminally charged with their use dating back to 2008."
The spokesman added that the temporary ban on visiting the shops was lifted on Monday based on the "mutual relationship of support and respect between RAF Lakenheath and the stores".