Police are struggling to cope with a spiral of violence within Britain's Turkish and Kurdish community.

Turkish murders in London

Mar 1994: Mehmet Kaygusuz, 33, shot while playing backgammon in Islington caf�. Unsolved. May 2001: Sami Mustafa, 26, and Hasan Mamali, 23, shot dead in Islington. Unsolved. Jul 01: Oguzhan Ozdemir, 26, shot and dumped on towpath in Tottenham. Unsolved Nov 02: Alisan Dogan, 43, died in mass brawl in Finsbury Park.

On Saturday a 43-year-old carpenter, Alisan Dogan, was stabbed to death during a mass brawl between more than 50 men in the Green Lanes area of Harringey, north London.

Knives, baseball bats and guns were used and 20 people needed hospital treatment.

It is the latest in a series of murders within the Turkish and Kurdish community linked to heroin, racketeering or feuding between various groups.

The National Criminal Intelligence Service (NCIS) says 70% of the heroin coming into the UK is brought in by ethnic Turkish gangs based in Britain.

These gangs tend to be based in north and east London but their tentacles spread to Birmingham, Glasgow, Merseyside and other conurbations.

Alisan Dogan left behind two children, Umit, 14, and Duzgun, 16

Suzanna Nuri, of the London Turkish Gazette, said Saturday night's violence seemed to be linked to a "turf war".

Another source within the community explained what lay behind the feud.

Yilmaz told BBC News Online the Kurdish separatist group PKK, which was engaged for 30 years in a war against Turkey, helped set up many businesses in London and demanded protection money in return.

Banned organisations

PKK and the far-left Dev Sol, now known as the Revolutionary People's Liberation Party (DHKP-C), are banned in the UK.

But in April PKK abandoned the military struggle and restyled itself as the Kurdistan Freedom and Democracy Congress (KADEK).

Yilmaz said a Kurdish mafia boss who lives in London had tried to muscle in on the PKK's turf.

The man - who cannot be identified for legal reasons but we shall call Mr B - operates through a gang of street toughs.

Yilmaz said: "Shop owners were happy to pay the PKK but not the mafia."

The tension came to a head when a Kurdish teenager who had joined the street gang tried to leave.

Communities in UK

100,000 Turkish Cypriots 50,000 mainland Turks 50,000 Kurds

He was beaten up several times and eventually went to the PKK for help.

"On Saturday at 4pm masked men turned up and smashed up some property. Youths from KADEK arrived at 6pm and retaliated."

Mr Dogan, a father-of-two who was helping to refurbish a caf�, died during the brawl that followed.

One businessman within the UK Turkish community, who declined to be named for fear of retribution, said they were being terrorised by criminals.

Mustafa told BBC News Online the majority of Turks, Kurds and Turkish Cypriots in the UK were law-abiding but he said a minority were creating havoc.

'Taking advantage'

He said Turkish gangsters, used to their homeland's tough laws, were "taking advantage" of the civil rights they enjoyed in the UK.

"Businessmen have to pay money out because they are frightened to go to the police. If you have children you would rather pay that money than have something bad happen. But most of the time these guys are nobodies," said Mustafa.

Haringey Council's crime and community safety spokesman Nilgun Canver said the police had set up a special taskforce which would start operating in Green Lanes on Monday.

Suzanna Nuri, of the London Turkish Gazette, said more ethnic Turkish officers were needed

Cllr Canver, who is herself Turkish, said CCTV cameras were also planned for the area.

She said some traders had started a petition to close down some of the cafes and clubs in the area which, they felt, attracted the wrong elements.

Some of these clubs were believed to host illegal gambling.

'Police should speak more Turkish'

Ms Nuri told BBC News Online part of the problem was too few police officers spoke Turkish.

She said there were only a handful of ethnic Turkish officers in the whole capital and added: "The only way the police are going to get on top of this is by getting to know what is going on in the community."

A Turkish Embassy spokesman told BBC News Online they had been pressing the UK Government to add KADEK to the list of proscribed organisations.

He said: "They are not fooling anyone by changing their name. They're the same people, doing the same sort of thing."

A PKK sympathiser said KADEK was not involved in extortion but said racketeers often used the PKK name to scare businesses into paying protection money.

A Metropolitan Police spokeswoman said ethnic monitoring was voluntary but she said the latest figures suggested there were 19 male and four female officers from the Turkish community.

Haringey borough commander, Chief Superintendent Stephen James, said: "The Met will not tolerate this level of violence and will respond with all of its resources and reassure the community of Haringey by enhancing police presence."

Anyone with information about the murder of Mr Dogan should contact the incident room on 020 8345 3731.