Police have arrested 12 people at an airbase in Gloucestershire, where US B-52 bombers are being prepared for deployment to the Gulf.
Police have invoked special powers
A group of people cut through fencing at RAF Fairford to get closer to the 14 warplanes which have been based there since Tuesday.
Defence Secretary Geoff Hoon gave permission for the bombers, which are expected to be at the forefront of any initial attack against Iraq, to be sited there.
A spokesman for Gloucestershire Police said: "There have been 12 arrests at RAF Fairford following criminal activity on the base in respect of cutting the fence.
Photos of Iraqi children have been stuck to the fence
"These persons have been arrested for criminal damage and aggravated trespass.
He added: "At no stage was the security of the base compromised."
Gloucestershire Police had stepped up patrols at the base and invoked special stop and search powers to detain anyone regarded as suspicious within a mile of the perimeter fence.
Earlier in the week police and the US Air Force issued a warning to members of the public about the dangers of trespassing on the grounds.
They said: "RAF Fairford is an active military base where aircraft manoeuvres are now taking place.
"We would like to highlight the inherent dangers which any
"Anyone who unlawfully gets into the base property could place their own lives and those of others in danger whilst aircraft movements and other associated activity is taking place."
The base has been the focus of many anti-war protests, and a peace camp has been set up in the grounds of a nearby pub.
Last week two women were arrested on suspicion of aggravated trespass after breaking through the security fence.
Lindis Percy, 61, from Hull, was charged and is due to appear before Cheltenham Magistrates on March 19. The other woman was released without charge.