PEOPLE are risking their lives by stubbornly ignoring warnings and walking on a live firing range.
Senior officers say only a combination of strict safety procedures and skilled marksmanship has prevented trespassers at Strensall, near York, from being killed or seriously injured by shrapnel or a stray bullet.
And they say the actions of a minority are jeopardising vital training for soldiers preparing for duty in war zones including Iraq and Afghanistan.
Each time soldiers become aware of a trespasser in the danger zone next to Strensall Common, firing of live rounds has to cease until the person has left. This can mean a morning or afternoon's training lost.
In the past three weeks sentries have been posted at the boundaries of the training area but some walkers have ignored their warnings and walked into an area where live ammunition is being fired.
Seven people have ignored warnings this week alone - some mistakenly believe the soldiers are firing blanks, while others claim they cannot be denied the right of access.
Children, walkers with or without dogs and even horse riders have entered the danger zone from all directions but Army bosses had been unaware of the scale of the problem because many trespassers entered from the north.
In that end of the danger zone they cannot be seen at all by soldiers training further south but risk death from bullets which have bypassed or ricocheted off the range's protective barriers.
Each year more than 31,000 personnel train on the ranges at Strensall, firing 1.5 million rounds of ammunition.
The base posts timetables of shooting on the ranges two weeks in advance and there are warning signs all around the perimeter. In addition, red flags are flown when firing is under way.
Some Territorial Army and cadet units have cancelled training at Strensall as they do not have enough people to stand sentry to watch out for trespassers.
Strensall has been a training camp for the military for more than a century and was bought by the then War Department in 1884.
By-laws permit public access on Strensall Common, except when the land is used for military training.
The danger area now accounts for almost half the total 1,500 acres of Strensall and Towthorpe commons.
"Once the military are operating on any part of the area civilians should not come in here at all," said Strensall training commandant Major Paddy Ennis.
"Some people think they have 'common rights' but unfortunately they haven't."
Until now the size of the area has prohibited it from being fenced off but the Ministry of Defence is currently investigating whether a fence could be put up at Strensall and other training ranges where there are similar problems with trespassers.