Derbyshire Police are urging parents and families not to buy ball-bearing (BB) guns for children this Christmas.
A BB gun is not a good Christmas present, say police
It has been illegal to carry a BB gun, any air weapon or imitation firearm in public since the start of the year.
Officers in the county are giving a warning about the dangers, as they think there is ignorance of the law.
Deputy Chief Constable Alan Goodwin said: "The message that having BB guns on the streets is illegal does not seem to be getting through to some people."
'Threat of arrest'
He said: "We want to remind everyone that they are putting themselves in danger if they play with or carry any guns in public.
"A BB gun may seem like a good stocking-filler but it could lead to the arrest and prosecution of the young person found with it in public."
"As we have said before anyone who brandishes any type of gun in public is putting him or herself in danger."
So far this year 25 people have been arrested by Derbyshire's armed response vehicles and 18 BB guns have been seized.
The forces said "many more" have been dealt with by unarmed officers.
During the summer posters warning of the new law were distributed to youth clubs and schools.