Racist tension between different ethnic groups in Britain is at its worst level for 50 years, according to a television documentary to be broadcast tomorrow.

Darcus Howe, one of the country’s most respected commentators on race issues, says in the Channel Four programme that violent confrontations between West Indians and Somalis in south London, and West Indians and Pakistanis in the West Midlands, are now endemic.

Mr Howe, who was born in Trinidad but has lived in Britain since the 1960s, documents a huge increase in stabbings, beatings, attacks on private property and street fighting between the groups.

The film paints a particularly bleak portrait of black-on-black violence between Somalis and West Indians living in the Woolwich and Plumstead areas of south London. Even while making the programme, entitled Who You Callin’ A Nigger?, Mr Howe’s film crew were attacked by a Somali “community worker”.

Later, Jobie, a 16-year-old West Indian, recounts how he was set upon by a large group of Somalis he recognised from his area while he attended an anti-racism concert in Greenwich. The damage to his skull was so severe that it nearly killed him.

Thousands of Somali asylum seekers, fleeing the civil war, settled in Woolwich in the early 1990s. Tensions between the arriving Somalis and more long-standing West Indian residents have now boiled over, the programme suggests.

Jobie says: “When I talk about them it makes me want to be sick. I think they are vermin. They are not a civilised people. They are black but a different kind of black To me they are like dirt. We have to clean up the dirt.”

Jobie feels that his views are justified. “I can remember one punching me, I can remember a brick hitting my head. I could see blood but I didn’t know where from. I felt my head. I went down, and I went unconscious. I ended up in an ambulance.”

The film-makers also show how Hyacinth, who has lived in Woolwich for 21 years, has become a prisoner in her home. She relates how one August evening last year she was sitting alone in her flat when she was subjected to a terrifying siege for nine hours.

“I could hear bricks coming through my house breaking all the windows,” she says. “We were so scared in here. [It went on] until quarter past five [in the morning]. Glass was flying everywhere — I was lying on the floor shaking.”

The incident was reported by a group of white boys who told police that the attack was carried out by 25 Somalis. Since the incident, Hyacinth has invested £800 in her own CCTV surveillance to monitor what happens on her doorstep.

“I don’t sleep until 2pm,” she says. “I am so scared they might come back. I hate the Somalis — they should go back to their country. They are a warring people. They don’t know about peace, they don’t know about love. They have no heart. Truly they are animals.”

Mr Howe says he is shocked by her language, describing it as similar to “a racist thug.” But he is also sympathetic — his director was “slapped around” by a Somali community worker “because we did not ask his permission to film his subjects”. He says: “Of everything I have seen I find the West Indian and Somali [violence] the hardest to stomach.”

He discusses the issue with a group of young West Indians at the Charisma barber’s shop in Woolwich. They, like Hyacinth, are vitriolic. One of his interviewees, wearing a baseball cap and a thick silver chain, says: “I had a Somali woman call me a nigger. You say to yourself, ‘Well you are not white. You’re black; you come from Africa’.”

“Their life over here is much better than it is over in Somalia. It’s better than the lives of people that live and grow up in this country.”

Yassin Ismail, a leader of the Somali community, criticised Mr Howe’s film, saying that it was an inaccurate portrayal of Somalis.

“They didn’t get the story from both sides — the documentary is absolutely biased,” he said. “There has been a lot of violence against Somalis. We have had a number of incidents were Somalis were stabbed, beaten and even shot.”

The Telegraph reported last December on Mr Howe’s research into racial tension between Pakistani and Afro-Caribbean residents in Walsall. The film, which will be screened at 11pm on Channel Four tomorrow, shows Pakistani youths in the town threatening Mr Howe and talking about “bashing” and “mashing” blacks and Jews.