London ? Britain lowered its terrorist threat level a notch Monday, a relief for weary travelers who have endured days of chaos at the nation’s main airports since security forces foiled an alleged plot to blow passenger planes out of the sky.

Attention focused on the role a radical Pakistani charity might have played in financing the terror scheme, allegedly with money that was meant to go to earthquake relief. Meanwhile, a court in London granted the government more time to interrogate the last of 23 people it is holding in connection with the plot.

The decision to drop the terror threat level to severe – where it was at before the jetliner scheme was scuppered – means passengers will be allowed a single, briefcase-sized bag aboard aircraft, and books, laptop computers and digital music players will also be permitted again.

Heathrow and other major London airports said they would not be able to implement all of the relaxed rules until today, but the scene at London airports was clearly improving during a drizzly, overcast Monday.

The British Airports Assn. said it was searching only half of passengers at Heathrow, greatly speeding up the flow. British Airways, the dominant carrier at the airport, canceled about one-fifth of its flights Monday, down from one-in-three that were canceled the day before.

A total of 68 flights had been canceled, or about 10 percent of the approximately 600 that take off daily from Europe’s busiest airport.

British police leave their temporary headquarters on the edge of King's Wood in High Wycombe, England, about 35 miles west of London. London's anti-terrorist police pressed ahead with a major search in the woodland area on Monday. The search will continue through today, though officers declined to say whether anything significant had been discovered.

“It’s a lot better today,” said Randeep Dahial, a 19-year-old security guard at Heathrow. He said that congestion had cleared noticeably although there were still crowds just inside the terminals.

Overnight, some travelers camped out at the airport’s restaurants, sleeping at tables amid piles of luggage. One woman balanced her two children atop a luggage cart as she wheeled across the terminal.

Threat still remains

Home Secretary John Reid cautioned that the easing of security measures and the lowering of the terror threat level did not mean that Britain was out of danger.

“I want to stress … that the change in the threat level does not mean that the threat has gone away,” he said at an early morning news conference. “There is still a very serious threat of an attack. The threat level is at severe, indicating the high likelihood of an attempted terrorist attack at some stage, and I urge the public to remain vigilant.”

Despite the warning, citizens could be forgiven for being confused by the mixed messages.

Prime Minister Tony Blair has remained on vacation in Barbados throughout the ordeal, allowing himself to be photographed in a floral bathing suit, an image that provided welcome fodder for political satirists and cartoon artists. Deputy Prime Minister John Prescott, who is running Britain in Blair’s absence, has made only the briefest of appearances on television.

Outside the airports

London’s anti-terrorist police pressed ahead with a search in a woodland area in High Wycombe, a neighborhood about 35 miles west of London where many of the arrests were made. The search will continue at least until today, a police official told The Associated Press. He spoke on condition of anonymity because he was not authorized to talk to the press.

Information about the terror plan was in short supply Monday. The government has yet to name all of the suspects or say where they are being held, and has not briefed reporters on their investigation since Thursday, allowing officials in the United States and Pakistan to take the lead on disclosures.

Pakistani authorities are holding 17 people – including a British citizen, Rashid Rauf, who they say has al-Qaida connections and was a key player in the plot. At least one of Rauf’s brothers was arrested in Birmingham during a counterterrorism sweep there.

The British High Commission in Islamabad said Monday it has not received confirmation that Pakistan is holding any British citizens, despite a written request for information. Aidan Liddle, a spokesman for the High Commission, said the two countries are cooperating in the terror investigation.

British House of Lords member Nasir Ahmed said a member of the Muslim community told him that some of the people detained in the alleged plot went to Pakistan to assist with relief efforts after an earthquake killed nearly 80,000 people last year.

“It may be that out of 22, there may be a number of them who have met someone from extremist groups in Pakistan or Kashmir,” Ahmed said. “Some may have met them without knowing that they were meeting (extremists) because they were helping out in the aftermath of the earthquake.”

The New York Times reported that money raised for victims of the earthquake was channeled to the plotters through the Pakistani-based charity Jamaat al-Dawat – a charge the charity denied.

The charity is not registered in Britain, but laws do not prevent British citizens from donating to or collecting for it.

Imran Gardezi, the spokesman for the Pakistani High Commission in London, said no special request for investigation of the charity had been made to Pakistan by the British government. A Pakistani intelligence official in Karachi told AP that American and British authorities had asked Pakistani agents to investigate transfers of large sums of money to five Islamic charities, but that the probe was not related to the jetliner plot.