LONDON - British Muslim groups said on Saturday Britain's policy on Iraq and Lebanon was fuelling militancy, as Pakistan said it had arrested a British al Qaeda member over an alleged plot to blow up transatlantic airliners.

A court gave British police more time to question 22 of the 24 suspects arrested in swoops on Thursday when officials said they had foiled a plot to use chemical bombs to bring down as many as 10 airliners flying from Britain to the United States.

The police crackdown, 13 months after four British Islamist suicide bombers killed 52 people on London's transport system, raised fears among British Muslims they were being demonized because of the militancy of a few.

In an open letter to British Prime Minister Tony Blair, leading British Muslim groups and politicians said his foreign policies on issues such as Iraq and the Israel-Hizbollah war were putting civilians at increased risk of attack in Britain and elsewhere.

"The debacle of Iraq and now the failure to do more to secure an immediate end to attacks on civilians in the Middle East not only increases the risk to ordinary people in that region, it is also ammunition to extremists who threaten us all," they said in the letter, published in the Times newspaper.

Many Muslims are critical of Blair's decisions to commit British troops to the 2003 U.S.-led invasion of Iraq and not to call for an immediate halt to the fighting between Israel and Lebanese Hizbollah guerrillas.

"We urge the prime minister to redouble his efforts to tackle terror and extremism and change our foreign policy," said the letter, whose signatories included six politicians from Blair's Labour Party.

Responding to the letter, Transport Secretary Douglas Alexander told Britain's Channel 4 television: "Nothing justifies the kind of actions which terrorists perpetrate."

AL QAEDA

Pakistan said it had helped thwart the alleged plot and that two Britons of Pakistani descent were among seven suspects who had been arrested in the country.

It said one of the Britons was an al Qaeda member who had played a leading role in the foiled plot that would have involved chemical bombs being smuggled on to aircraft disguised as drinks.

"He is a British citizen of Pakistani origin. He is an al Qaeda operative with linkages in Afghanistan," Interior Minister Aftab Ahmed Khan Sherpao told Reuters.

Sherpao said the arrest of the man, identified as Rashid Rauf, had led to the arrests in Britain.

On Friday, British police released one of the 24 people arrested in Thursday's swoops without charge. A court granted police a warrant to hold 22 suspects until next Wednesday. A decision on the other suspect will not be taken until Monday.

Britain named 19 of those arrested, who were aged from 17 to 35, and ordered their assets to be frozen.

British media said the suspects were mostly British-born men of Pakistani origin, three were converts to Islam and one was believed to be a security guard at London's Heathrow airport.

Friends of those arrested said the men had led ordinary lives and had jobs such as being a taxi driver or pizza delivery man.

The Independent newspaper said Britain's security service and police believed a Britain-based cell, assisted by al Qaeda members, had planned to start a series of suicide bombings on U.S.-bound planes as early as Friday or Saturday.

It said officers investigating the plot had found bomb-making equipment.

Chaos at airports eased on Friday as travelers grew used to tough new security measures, including a ban on liquids being carried on to flights from U.S. or British airports.

But British Airways warned customers to expect further flight delays and cancellations at Heathrow airport on Saturday.