British Muslims claim they are being victimised by police who, they say, are using their powers of stop and search to harass them in the climate of fear over terrorist attacks.
Lawyers and groups representing the Islamic community say they are receiving a growing number of complaints from people who have never been in trouble with the police but who report being stopped in the street or in their cars, or having their homes searched.
Some have been pulled over for questioning at airports or ferry terminals, and all allege they have been picked on for no apparent reason other than that they are Muslim.
Massoud Shadjareh, chairman of the Islamic Human Rights Commission, said police activity directed against Muslims had risen sharply since September 11 2001. The group recently printed 500,000 leaflets informing Muslims of their legal rights.
Mr Shadjareh pointed to Home Office figures which showed that in 2002-03 there were 32,100 searches overall under the Terrorism Act, 21,900 up on the previous year and 30,000 more than in 1999-2000. He claimed Muslims were the subject of a hugely disproportionate number of these.
"I recently gave a workshop in Luton and of 12 people in the group, seven had been stopped and searched by police. Often, they are people who have lived in the UK for decades and have never broken the law in any way," Mr Shadjareh said.
Khalid Sofi, secretary of the legal affairs committee of the Muslim Council of Britain, said anti-terrorist legislation had given rise to Islamophobia. "The whole Muslim community is seen as suspect, and there is worrying evidence it is being abused by police to harass ordinary citizens."
Ruhul Tarafder, campaigns coordinator for the 1990 Trust, a black-led human rights organisation, carried out research last November and December in Tower Hamlets, east London, and in Westminster, where he discovered many Muslims who had had bad experiences with the police.
"Muslims from 14 years old and upwards had come to view being stopped by the police as part of normal life," he said. "No real reasons were given, though anti-terrorist legislation was frequently cited.
"Often it was when they were wearing traditional clothes or if they had Muslim-style beards. Muslims understand there is a security threat but it doesn't mean they should be treated unfairly."
Leroy Logan of the Black Police Officers Association said: "What we are hearing gives us a worrying sense that section 44 [of the anti-terrorist legislation] is being used by police disproportionately."
The resentment expressed by Muslim groups stands in sharp contrast to the views of the general population on how the so-called war on terrorism is being conducted in Britain. Most voters feel the government is handling the crisis well, according to the results of a Guardian/ICM poll.
The survey was carried out in the aftermath of the Madrid train bombings and the warning by the Metropolitan police commissioner, Sir John Stevens, that a terrorist attack on London was inevitable.
It shows that 50% of the public believe that the government is handling the crisis "fairly well," and a further 8% think it is coping "very well".
This contrasts with 39% of voters who think the government is doing either "fairly badly" or "very badly" when it comes to handling terrorism.
The findings come after David Blunkett rebuked Sir John for making people "jumpy" by suggesting that a terrorist attack was inevitable. In an interview with the Sunday Telegraph the home secretary said: "There has to be a balance between telling the truth and reassurance. Otherwise people are jumpy without it having a good effect."
Figures for the number of times police use their stop and search powers on Muslims are sketchy and do not include other counterterrorist activity, such as house searches. Scotland Yard statistics give a breakdown by ethnic group, and show a slight increase in the number of Asians, who are mainly Muslim, being stopped by the Metropolitan police. From April 2000-01 it was 9.9%; 2001-02 11.8%; 2002-03 12.2%; and 2003-04 11.7% so far.
Mr Shadjareh said police concentration on Muslims was racist and counterproductive, as it alienated the very community police needed to help defeat terrorism.
"People carrying out bombing attacks are not going round with long beards, looking like imams, praying in mosques all day," he said. "They will be clean-shaven, have girlfriends, drink in pubs. They will not stand out as Muslims or they will be disguised."
David Veness, the Metropolitan police assistant commissioner in charge of specialist operations, which includes anti-terrorism, admitted there was a dramatic increase in counterterrorist activity. But he insisted no community was being unfairly targeted.
"It is clear that this unprecedented level of activity causes concern in some communities," he said. "Other communities may believe they are being unfairly identified with terrorists. We understand these concerns but would categorically say that no one is being targeted by police because of their culture or faith.
"For us to do so would be the most counterproductive course of action we could take because it is not police actions alone that will ultimately defeat terrorism but the combined actions of all communities."
A Met spokeswoman said police were aware of the negative impact some people felt police actions were having in the current state of high alert, but said senior officers met regularly with Muslim representatives and encouraged feedback.
ยท ICM interviewed a random sample of 1,005 British adults by telephone from March 19 to 21. Interviews were conducted across the country and the results weighted to the profile of all adults.