London Metropolitan Police deputy assistant commissioner Peter Clarke said the investigation uncovered bomb-making equipment and martyrdom videos on computers belonging to some of those arrested. ((Tom Hevezi/Associated Press))

Eleven of the 23 people detained in connection with the alleged plot to blow up transatlantic airliners have been charged, British police said Monday.

Eight people are charged with conspiracy to commit murder and preparing acts of terrorism, deputy assistant commissioner Peter Clarke, head of Scotland Yard's anti-terrorist branch, said during a news conference in London.

The names of those charged are Ahmed Abdullah Ali, Tanvir Hussain, Umar Islam, Arafat Waheed Khan, Assad Ali Sarwar, Adam Khatib, Ibrahim Savant and Waheed Aman.

Two others are charged with failing to disclose information about potential acts of terrorism, while a 17-year-old is charged with possession of articles useful to a person preparing acts of terrorism.

The suspectshave been held since Aug. 10, when British police announced they had thwarted a suspected plan to set off bombs on at least 10 flights travelling between the United States and the United Kingdom.

One woman has been released without charge, leaving 11 people still in custody, said police.

'Martyrdom videos' found: police

Investigators also found bomb-making equipment and martyrdom videos on computers belonging to some of those in custody, said Clarke. He didn't say whether the people in custody appeared in the videos.

Investigators have completed 69 searches of houses, apartments, businesses, vehicles and open spaces, he said. They've found 400 computers, 200 mobile phones and 8,000 media storage devices such as memory cards, CDsand DVDs.

"I would like to reassure the public that we are doing everything we can to keep you safe so that you can live your lives without being in constant fear," said Clarke.

Airports clamped down on security after theAug. 10 announcement, banning liquids and items with gel-like consistencies from carry-on luggage. It's believed the suspected bombers planned to use a chemical explosive.

Hundreds of thousands of travellers were forced to toss out everything from bottles of liquor to lip balm to perfume.

In Canada, the company that runs airport duty-free stores laid off 200 workers because it wasn't allowed to sell bottles of alcohol or perfume.

The rules were slightly relaxed last Friday, allowing passengers to purchase the items if they put them in checked luggage.