By Frank Gardner BBC security correspondent

US Government plans to focus extra security measures on people from the Middle East have brought accusations of racial discrimination.

As part of the war on terror, the US intends to fingerprint and photograph tens of thousands of visitors and build up databases on individuals, especially Arabs and Muslims, known as "profiling".

We have this fear in our community that we are being watched

Fadhi Kiblawi, student

Many Americans have welcomed the idea, but most Muslims are appalled.

They say the plan is racist, ineffective, and could end up alienating the very people the US Government needs, if it is to defeat al-Qaeda.

In the eyes of many Americans, Arabs and Muslims are all potential terrorists. In the post 11 September backlash, Muslims have had to spend thousands of dollars on security for their mosques.

Muslim fears

Student Fadhi Kiblawi, from Virginia, used to help organise support for the Palestinians - but now does not dare express his views.

You can't wear the right clothes, put your hair in the right way, someone out there is going to decide you aren't trustworthy

Christie Lopez, civil rights lawyer

"We have this fear in our community that we are being watched, members of our own community, detained, profiled, so on and so forth... we know that we personally have done nothing wrong."

This perceived racial discrimination has gone so far that the civil rights lawyer Christie Lopez believes that American civil liberties have become a casualty.

"It is devastating because you realise there is no real system out there, that there is nothing you can do to prevent yourself being called a terrorist.

"You can't wear the right clothes, put your hair in the right way, someone out there is going to decide you aren't trustworthy. There is no system to protect you and that is frightening."

Unfortunately for the law-abiding Muslim majority, the most imminent threat to US security comes from Islamic extremists.

The authorities cannot build up databases on all 35 million visitors who enter the US annually. So, privately, they admit they will be focusing on Arabs.

Arabs alienated

However, the resentment this causes could be costing the US a precious resource - intelligence.

Attorney General John Ashcroft is the strongest advocate of the new measures

Student Jennifer Attallah, who speaks Arabic and English, said she would now think twice about helping the FBI or CIA in the war on terror.

"When I have talked about that possibility with my friends at university the first thing I hear is 'don't do that - don't spy on your own people'. So I haven't pursued that," she said.

That is America's loss, because it needs Arab informers if it is going to win the war on terror.

The US authorities do not know where the next al-Qaeda attack is coming from. What they do know is that Islamist plotters have already been dispatched to America, hoping to blend in.

In the government's effort to make up for past intelligence failings, it may be making enemies of the very people who could help it find them.