By Chris Summers BBC News Online

Spiralling violence between gangs in London's Tamil community has led to four violent deaths and up to 200 other incidents in the last two years.

Police say the violence is getting worse.

Commander Richard Bryan, whose patch in north west London has witnessed much of the violence, has set up a cross-London co-ordinating group in an attempt to root out the gang culture.

He said: "The vast majority of the Tamil community in London are law-abiding and want to get on with their lives in peace but a significant minority represent a problem which needs to be addressed."

London boroughs affected

Brent Harrow Croydon Ealing Newham Hillingdon

Cmdr Bryan said those causing much of the trouble were "loose associations of individuals" but he said they needed to nip them in the bud before they became established gangs.

The conflict in Sri Lanka began in the early 1980s when the Liberation Tigers of Tamil Eelam (LTTE) sought independence for the north and east of the island.

The UN estimates 917,000 people have left Sri Lanka since 1993 and many of the diaspora have come to Britain.

Thambirajah Jeyabalan is editor of Thesam (Nation), a monthly magazine which serves London's 100,000-strong Tamil community.

Youths are searched for weapons at a Tamil-language cinema

He said the gangs were unsophisticated and poorly organised but could be extremely violent.

Mr Jeyabalan told BBC News Online: "The fights are between people from different villlages.

"The main ones involved are from Valvettithurai (they're known as VVT), Mannar and Ariyalai."

He said the 500,000-strong Tamil community in Ontario had suffered even worse violence until the Canadian police cracked down on them four months ago.

The two main gangs involved in Canada are the AK Kannan and Seelapu, the latter being an ally of the VVT.

No political connection

In Canada the leader of the AK Kannan was a sworn enemy of the LTTE.

But Cmdr Bryan said the violence in London did not appear to have any political overtones, although some of those involved may be former Tamil Tiger fighters.

The LTTE was added to the list of proscribed organisations by the UK Government last year.

Mr Jeyabalan said there had been occasions when young Tamils from Toronto or Paris were flown to London especially to carry out attacks.

They then flew home.

Various motives

Cmdr Bryan said the motives for the violence were many and complex, but they included rivalry and vendettas stemming from their home villages in Sri Lanka and simple criminality.

"There is evidence these gangs are involved in fraud, especially credit card fraud, and human trafficking," he said.

Cmdr Bryan said it was not uncommon for refugees from Sri Lanka's civil war to pay traffickers from their own community to smuggle them into Britain.

Cash and weapons seized from Canadian Tamil gangs

Once in the UK they are often beholden to the traffickers, and are forced to carry out credit card frauds or assist in violent attacks on rival groups.

Cmdr Bryan said many of the attacks were "tit-for-tat" and there had been a dangerous escalation of the violence in the last two years.

Paul Sathianesan is a councillor in Newham, east London, and he says he regularly hears about attacks but many of the victims refuse to go to the police for fear of retribution.

Cmdr Bryan admits there is a high level of unreported crime.

There are around 100,000 Tamils in London

But the Metropolitan Police is responding by introducing high visibility policing at Tamil weddings and religious festivals, and by seeking better intelligence to enable them to intervene in feuds before they escalate into murderous violence.

Mr Jeyabalan is confident the police can get on top of the problem: "If the police take firm action against these people they can crack down within months."