Eleven people were yesterday charged over the alleged plot to explode bombs on passenger planes heading from Britain to the United States.

Scotland Yard said the investigation into the alleged plot had recovered chemicals that could be turned into explosives, equipment to make bombs, suicide video notes from some accused of involvement in the plot, and a manual on making explosives.

Eight men have been accused of planning to "manufacture and smuggle the component parts of improvised explosive devices on to aircraft and assemble and detonate them on board," said Susan Hemming, the head of counter-terrorism at the Crown Prosecution Service.

The men are charged with two offences of conspiracy to murder, and with the new offence of preparing acts of terrorism, which became law after the attacks on London's transport network on July 7 last year.

Three others have been charged with other terrorism offences: one of possessing items useful for terrorism, and two, including Cossar Ali, 23, of failing to tell the police about what she is alleged to have known about terrorism.

Mrs Ali's seven-month-old child will be cared for by relatives, it is believed. Her husband, Ahmed Abdullah Ali, is charged with conspiracy to murder.

One woman was released without charge early yesterday, and a further 11 suspects remain in custody.

Ms Hemming said: "These individuals are only accused of these offences and they have a right to a fair trial."

In an unusual move, at a press conference with the CPS, Peter Clarke, head of Scotland Yard's anti-terrorist branch, gave details of some of the evidence that will be used against the accused.

It includes audio and video surveillance before the arrests, the recovery of chemicals such as hydrogen peroxide that can be used in making bombs, batteries and video suicide notes.

Mr Clarke said: "There is evidence from surveillance carried out from before August 10. This includes important, indeed highly significant, video and audio recordings.

"I can also tell you that since August 10 we have found bomb-making equipment. There are chemicals including hydrogen peroxide, electrical components, documents and other items.

"We have also found a number of video recordings. These are sometimes referred to as martyrdom videos. This has all combined to give us a clearer picture of the alleged plot."

Mr Clarke said the scale of the investigation was "immense" and would "span the globe".

He said 69 searches had been carried out, including in the woods in High Wycombe, at residential and business addresses and vehicles.

Hundreds of computers, thousands of data-storage devices such as CDs and DVDs, and hundreds of mobile phones had been recovered.

They would be examined for evidence, Mr Clarke said.

"I would like to reassure the public that we are doing everything we can to keep you safe - for you to live your lives without being in constant fear. However, we must be realistic. The threat from terrorism is real. It is here, it is deadly and it is enduring," he said.

"As we all look for explanations we cannot afford to be complacent and ignore the reality of what we face."

Eight of those charged are from east London and two are from High Wycombe, Buckinghamshire.

A 17-year-old male, who cannot be named for legal reasons, is accused of having a book on making explosive devices "some suicide notes and wills with the identities of persons prepared to commit acts of terrorism and a map of Afghanistan containing information likely to be useful to a person committing or preparing an act of terrorism", according to the charges against him.

Detectives have authority to detain the 11 other suspects until late tomorrow, by which time they must charge or release them, or apply to the high court for a further extension of custody.

The disruption of the alleged plot led Britain to raise its terrorist threat level to critical and to widespread disruption at airports as tough security measures were imposed.

Those charged are expected to appear at City of Westminster magistrates court this morning.


THOSE CHARGED

Eight people are charged with conspiracy to murder and preparing acts of terrorism, under section five of the Terrorism Act 2006. They are: Ahmed Abdullah Ali, Tanvir Hussain, Umar Islam, Arafat Waheed Khan, Assad Ali Sarwar, Adam Khatib, Ibrahim Savant and Waheed Zaman. A 17-year-old male, who cannot be named for legal reasons, is charged with possessing articles useful to a person preparing an act of terrorism. Mrs Cossar Ali and Mehran Hussain are charged with failing to tell police about information they had about terrorism.