British police detained another suspect Tuesday in an alleged plot to blow up jetliners over the Atlantic, the first arrest in the case since the plot was foiled last week after 24 other people were taken into custody.

The announcement came after police said they raided two Internet cafes in the investigation of an alleged plot to blow up jetliners over the Atlantic, and a news report said officers found firearms in a search of a woodlands near where some of the suspects were arrested earlier.

Travelers also continued to face problems at Britain's main airports, where delays and cancellations exacerbated confusion over shifting rules governing hand luggage.

CountryWatch: Great Britain

London's Metropolitan police said the suspect was detained around noon in the Thames Valley area just west of London but offered no more details, including the person's gender or identity.

"A suspect has been arrested in connection with the investigation and is in custody in the Thames Valley area," a police spokeswoman said, speaking on condition of anonymity to comply with department rules.

The developments came after several days of a near lockdown on information after the plot was revealed on Thursday, with the government saying 24 people had been detained.

One suspect was released without charge on Friday and the remaining 23 had their detention extended through Wednesday.

The two Internet cafes were raided Thursday in central Slough, 25 miles west of London, not far from the neighborhood in the town of High Wycombe where several suspects were arrested last week, Thames Valley police said. They didn't say what, if anything, was found.

Police said they had increased their presence in Slough, but urged people to remain calm.

"There is no intelligence to suggest that there is any specific terrorist threat to anyone in this area," Chief Superintendent Brian Langston said.

Meanwhile, the British Broadcasting Corp. said a search of some suspects' homes and of a woodland area in High Wycombe turned up several firearms and other items of interest. It was not clear if they were related to the alleged jetliner plot, which authorities say involved a plan to smuggle liquid explosives aboard flights hidden in hand luggage.

On Tuesday, opposition Conservative Party leader David Cameron accused the government of talking tough but doing little to counter extremism and boost counter-terror efforts.

Prime Minister Tony Blair, he said, failed to follow through on a plan unveiled after last year's London transit bombings to crack down on radical clerics and help Britain's moderate Muslims face down militants in their communities.

"We need follow-through when the headlines have moved on," Cameron said. "But precious little has actually been done."

At London airports Tuesday, passengers were allowed to take a single, briefcase-sized bag as a carry on and were also permitted to have mobile phones, laptops and other electronic devices. Cosmetics, gels, toothpaste, liquids and sharp objects remained forbidden.

Despite the easing of the rules, British Airways canceled a fifth of its flights from London on Tuesday, the same as on Monday. BA cut 52 flights, including four bound for the United States. Budget airline Ryanair canceled eight flights out of Stansted airport.

At Heathrow, Europe's busiest airport, travelers again were forced to wait outside before taking their turn at a check-in desk. Inside the terminals, stranded and delayed passengers slumped against piles of luggage or tried to sleep on rows of chairs.

"I'd rather have the increased security, but the people are just so irritable and angry," Reema Alhabeeb, 16, said after waiting two hours outside a terminal hoping to fly home to Boston.

British Defense Secretary Des Browne said work was under way on new permanent security requirements for airports, but declined to say what the new measures might be.

A report by The Times newspaper said officials were considering a system of passenger-profiling that would select people behaving suspiciously, who had an unusual travel pattern or were of a certain ethnic or religious background.

Leaders in the Muslim community criticized that approach, saying it would further isolate British Muslims.

"The government needs to think very, very carefully before it considers putting this measure into practice," said Inayat Bunglawala, a spokesman for the Muslim Council of Britain. "There is concern that such profiling would perhaps only contribute to further alienating a group whose close co-operation is essential in countering terror."

The government dropped the terror threat level Monday to severe -- where it was before the alleged jetliner plot was thwarted.

Interrogations continued in an atmosphere of secrecy. Tough new anti-terror laws give the government up to 28 days to hold suspects without charge, but they must periodically go before a judge to make a case for continued confinement.

Investigations were also under way in Pakistan, where authorities held 17 people, including British citizen Rashid Rauf, who they said has al-Qaida connections and was a key player in the plot. At least one of Rauf's brothers was arrested in England during the sweep here.

Pakistan's Foreign Ministry said Tuesday that it might extradite Rauf to Britain.