By Clare Purdy
BBC News, Manchester
A "novelty" gun, designed to fit on a key-ring, is no less dangerous than a pistol, police are warning.
The three-inch key-fob guns are illegal, inaccurate and deadly, according to police, who are working to get the weapons off the UK's streets.
Greater Manchester Police (GMP) is at the forefront of the operation, as 14 of the 16 seized nationally since 2003 were discovered in the county.
Possession of the firearm carries a mandatory five-year prison sentence.
Inspector Steve McGarry, who works at GMP as part of the national Criminal Use of Firearms Group, says the key-fob guns are notoriously unreliable, and inaccurate. But they are deadly at point-blank range.
The recent inquest of 19-year-old Fabian Flowers in Manchester heard how it was believed the teenager died when he shot himself in the head, apparently trying to test the gun's faulty mechanism.
The inquest recorded an open verdict. The gun which killed Fabian was never found.
The weapons change hands for a couple of hundred pounds each and originate from Bulgaria, where they are legal flare guns.
But many have been modified to fire .25 calibre bullets - and can be made into lethal weapons.
Insp McGarry said: "Not only are these guns a danger to the people using them - there have been incidents where they have fired in people's pockets - but they are a danger to anyone in the vicinity of them being fired because they are so inaccurate."
The guns are about three inches long and operate with two barrels, but do not have effective safety catches.
Police are keen to stress that those caught in possession of key-fob guns face the same penalties as the more conventional firearms.
Insp McGarry said: "Although they are put across as a novelty item, or you are made out to have 'street cred' if you have them, if you are found in possession, it is mandatory five-year sentence."
Greater Manchester Police stopped a man in the city in June last year, after officers saw him speeding.
He had a key-fob gun in his car and was later sentenced to six and a half years for being in possession of a firearm and a further two years for being in possession of the ammunition.