By Nick Miles BBC correspondent in Mexico City

Mexico City's police officers are being issued with special new uniforms to make it harder for criminals to impersonate them.

The crime rate has been soaring in the city of 20 million people and the situation is not helped by the poorly paid and trained police force.

An added problem has been that fake police uniforms are readily available on the streets for those people who want to buy them.

POLICE CHIEF'S PLANS

Issue new uniforms in special material Dress mounted police in traditional costumes Send officers to law school

The city's police chief, Marcelo Ebrard, said the new uniforms will help bring an end to a growing trend of people dressing up as policemen and then committing crimes.

His plan is to fit future uniforms with microchips and make them out of a material that is not available to the general public.

He says the plan is in its early days; he has not revealed what the special material will be or how on a dark night people will be able to tell what is real and what is fake.

It is just one of a series of novel ideas from Mr Ebrard to cut crime and re-establish faith in the city's police force known for bribe-taking, armed robbery and occasionally hostage-taking.

Some of his initiatives - like launching a mounted police force dressed in 19th Century cowboy costumes to protect tourists - have been ridiculed.

Others like his plan to send officers who as a rule leave school at 16 to attend university law courses have been widely welcomed.

Multi-tiered approach

Over the last few months, Mr Ebrard has been working closely with the former mayor of New York, Rudy Giuliani, who has just been awarded a lucrative contract to advise on how his successful zero-tolerance policing policy can be brought to Mexico City.

There seems to be a unanimous agreement on the need for a multi-tiered approach to fighting crime and police corruption.

Certainly the latest proposal, to make sure police uniforms are not used by criminals would not work alone.

Perhaps the next focus should be on police cars.

Customising a private vehicle with police number plates and flashing lights is on the rise, a snip for your average criminal at just $700.