It's barely noon on a recent day in this blighted Leeds suburb, but Gareth McCourt, a construction worker with the words "100 per cent white" tattooed across his belly, is already thirsting for blood.

"There's going to be a lot of trouble," promises McCourt, 21, as he drains another pint at the Tommy Wass pub, a Beeston hangout for white men with shaved heads and abundant tattoos.

"There's too many Asians around here. And what happened is too close to home, ain't it?"

Across town, where the Muslims live, a cluster of young Britons of Pakistani heritage cup their hands in a beckoning gesture to bring on the fight.

"We can handle ourselves," says Shair Kaman, 28, a property manager whose perfect English blends cockney and Pakistani accents. "If they come at us, we'll come at them."

In Beeston and other British communities with Muslim immigrant populations, ethnic tension has soared since news broke that the four suicide bombers in London's terror attacks July 7 were British citizens or residents, three of Pakistani heritage.

Radical elements on both sides "want to provoke. They want to create division and discord", warned Shahid Malek, a Muslim member of Parliament, in a recent interfaith gathering in Dewsbury, a former mill town near here where one bombing suspect lived. "If you are provoked, they win."

More violence, Malik added in an interview, could lead to further militancy among disaffected Muslim youths.

Local officials are particularly concerned about violence in Beeston, Dewsbury and other communities in the West Yorkshire midlands where the four bomb suspects lived.

Some fear the areas could be swept by race riots similar to those that convulsed three British towns for several days in mid-2001 after white youths attacked a South Asian man's home.

Those riots, in which mobs of white and South Asian youths clashed with police and each other as they trashed stores, pubs and cars, swept areas similar to the bombers' hometowns: former white, blue-collar enclaves that drew thousands of Pakistani, Bangladeshi and other Muslim immigrants to mill jobs that were plentiful a few decades back. But the mills have closed, making work scarce for everyone.

Already in Beeston and Dewsbury, attacks against Muslims are cropping up like boils. Last week in Beeston, a mob of about 60 white men descended on a pub and began insulting a couple with dark skin. Eight men were arrested for disorderly conduct.

That same night, a white man lunged at a Pakistani immigrant as he left a Beeston fast-food takeout joint and screamed between curses, "Get out of my country, you Muslim terrorist". In a stroke of luck, a passing patrol car stopped the commotion. "But I'm still terrified to walk the streets," the immigrant, Haw Nawaz, 44, said.

In Dewsbury, a Pakistani taxi driver trembled as he recounted how a white man tried to strike him in his cab last week.

Police and community groups are fanning through neighbourhoods distributing leaflets in half a dozen languages that give victims hotline numbers and the warning, "Harassment of any form will not be tolerated".