black men openly wearing firearms on the streets and in nightclubs.

"It's a very unhealthy fashion but there is a cultural aspect to it within a section of black youths who follow 'gangster rap' and that type of music."

He added that there had been reports of young black men openly wearing firearms on the streets and in nightclubs.

"It can be extremely difficult for our officers and the members of the public to tell a real gun from a replica one," he said. He added that the Met would support a ban on replica firearms in public places.

Police chiefs and the Gun Control Network, a lobby group, are pressing for greater restrictions on the availability of imitation firearms. The chairman of the Gun Control Network, Gill Marshall-Andrews, said: "The situation is getting worse by the day and the proliferation of these weapons is very alarming."