The scheduled appearance at the City of Westminster Magistrates Court would be the first time that the suspects, all of whom were charged Monday with terrorism offenses, appear in public since being arrested on Aug. 10.

Eight people were each charged with two offenses - conspiracy to commit murder and preparing acts of terrorism. One person, a 17-year-old, was charged with possession of articles that could be used to prepare a terrorist act and two people were charged with failing to disclose information that could help prevent a terrorist act.

One person was also released without charge, while 11 remain in custody but have not yet been charged.

Nine of those charged are from London, according to a Bank of England list of suspects whose assets were frozen following the arrests. Two are from suburban High Wycombe, 30 miles northwest of London.

Investigators warned that the case was still being investigated.

"Fingerprints, DNA, electronic data, handwriting comparisons, chemical analysis and indeed the full range of forensic disciplines will be used," Peter Clarke, the head of the Metropolitan Police's anti-terrorism unit told reporters after the Crown Prosecution Service announced the charges.

"The meticulous investigation of all this material will take many months. All the data will be analyzed. There will be thousands of forensic examinations and comparisons," he said. "The scale is immense, inquiries will span the globe."

British officials also confirmed on Monday for the first time that the plot involved the manufacture of explosives, which would then be assembled and detonated on board airliners.

"There are chemicals, including hydrogen peroxide, electrical components, documents and other items," Clarke said. "We have also found a number of video recordings ¡ª these are sometimes referred to as martyrdom videos. This has all given us a clearer picture of the alleged plot."

The details of the charges against one man, Mehran Hussain, allege that sometime between Sept. 23, 2005, and Aug. 10 - the day police announced the plot had been disrupted - he had information which could have prevented a terrorist act and didn't disclose it.

More than 8,000 items of data storage, such as compact discs, DVDs and memory sticks, were found in police searches. Maps of Afghanistan, suicide notes from willing terrorists and books on explosives were also seized, officials said.

For the 11 people still in custody, whose names have not been released by police questioning continues. Investigators have until Wednesday to decide if they will be charged, released, or if police will ask a judge to grant them more time to investigate.

"Their position is being assessed on a regular basis with a view to considering the need to keep them in detention," said Susan Hemming, who heads the Crown Prosecution Service's Counter-Terrorism Division. "We cannot yet make a decision about whether further charges will follow or if a further application for detention will be made on Wednesday as the evidential picture is continuously developing."

Investigators did not reveal if the suspects were linked to al-Qaida.

Pakistani authorities have linked several people arrested there in the alleged bomb conspiracy to al-Qaida militants both in Pakistan and in neighboring Afghanistan, where Islamic militants are fighting the U.S.-backed government.

Among those being interrogated in Pakistan is Rashid Rauf, a Briton of Pakistani descent who officials in the South Asian nation say played a key role in the plot. His brother, Tayib, who was videotaped at a grocery story in Birmingham just hours before he was arrested Aug. 10, was not among those charged.