By Jon Silverman Home affairs analyst

In 1994, a detective with the Flying Squad was wounded after one of two armed robbers he was pursuing fired a reactivated Czech-made Skorpion machine gun at him.

It is thought to be the first time that a reactivated weapon had been used in London.

The fact that it was manufactured in Eastern Europe is also significant.

Senior law enforcement officers had already warned the countries of the former Soviet bloc were a veritable arms bazaar, with millions of ex-military weapons in circulation.

A gun made to look like a mobile phone has been found in London

The Balkan conflicts of the mid-1990s generated another glut of weaponry ripe for the black market and frequently destined for Western Europe.

In Albania, with a population of three and a half million, there were said to be four million guns.

In 1997 alone, more than 650,000 firearms were seized.

No-one can be sure how many others have found their way to the UK over the years.

And it is not just the volume of weaponry which is causing alarm.

Disguise

The National Criminal Intelligence Service - one of the participants at Friday's summit - has alerted police forces to the ingenuity with which Eastern European gun manufacturers have disguised their products.

A gun made to look like a mobile phone has been found in London.

Others designed as key rings are intended to avoid airport security.

Guns resembling screwdrivers, cigarette packets and pens have all turned up in the UK.

Arms hauls are increasing

To try to identify the source of these guns and track the ways in which they are trafficked across Europe, NCIS set up the National Firearms Tracing Service.

It already liaises with other police and intelligence agencies within the European Union and with Interpol and it is possible that it may be asked to take on extra tasks as a result of the summit.

The Home Secretary, David Blunkett, told a conference at Lancaster House a month before Christmas that the Balkans was the "gateway to Europe for organised criminals".

For the gangs, smuggling weaponry is more of a sideline than a main source of profit.

Nine out of ten firearms used by criminals in the UK have been manufactured abroad

The really big money lies in drug trafficking, smuggling illegal immigrants and running vice rings.

But NCIS believes that established routes across Western Europe are probably also used to bring in small quantities of firearms as well.

And if, as a result of the government's package of measures, guns already in the UK become scarcer, the Balkan gangs will have a bigger incentive to try to make up "the shortfall " by smuggling.

But the Balkans is only one part of the equation.

'Immense task'

Nine out of ten firearms used by criminals in the UK have been manufactured abroad.

Recent recoveries include weapons from Argentina, Australia, South Africa, Israel, Croatia and Switzerland.

And one of the underworld's most active armourers, convicted in 1999, concentrated on converting legally imported MAC-10 sub machine guns from the United States.

With weapons also brought in by post, parcel couriers and ordered through the internet, the challenge for the law enforcement agencies is self-evidently immense.