Police in Derbyshire are calling on children to hand in ball bearing guns.
The guns look realistic even to specially trained officers
It comes after armed officers are called out regularly to incidents involving the currently legal toy weapons known as BB guns.
Over the past two years the number of incidents of people being injured by the guns, which police say are virtually indistinguishable from real guns, has increased rapidly.
The guns can be bought from toy shops but police say they are increasingly being used as weapons by teenagers.
Chief Inspector Chris Brown said: "They look like guns, they feel like guns and it is almost impossible to distinguish them from the real thing.
"They fire a small ball bearing which if it hits someone it could cause reddening of the skin and maybe puncture the skin and if it hits somebody in the eye the injuries could be quite serious.
"It is quite inappropriate that youngsters are using these in public."
Anyone who has one of these guns or finds one is urged to take it to any police station where it will be disposed of.
Youngsters who do hand their weapons in can swap them for free Ram's tickets, CD's and Internet Access.