Eight men accused of plotting to commit murder and cause mayhem with radioactive materials, toxic gases, chemicals or explosives appeared in court Wednesday in a case linked to a U.S. terror alert this month.

The defendants included an alleged senior Al Qaeda (search) operative also charged with scouting prominent financial targets for terror attacks in the United States — including the New York Stock Exchange, the World Bank and the International Monetary Fund.

One defendant, Dhiren Barot (search), 32, was charged with possessing reconnaissance plans for the New York Stock Exchange, the International Monetary Fund, the Citigroup building and the Prudential building; and with possession of notebooks containing information on explosives, poisons, chemicals and related matters.

A U.S. official in Washington, speaking on condition of anonymity, said Barot is the suspected Al Qaeda figure previously identified as Abu Eisa al-Hindi or Abu Musa al-Hindi (search).

After the Aug. 1 terror alert involving those buildings and the World Bank in Washington, the U.S. government acknowledged it had no evidence of plans for imminent attacks. The charges specified that Barot had the plans as early as Feb. 19, 2001.

Prosecution lawyer Sue Hemming said the eight suspects were motivated by "a strong and deeply held ideology" and were willing to carry out extreme acts. She said police have about a hundred computers and thousands of files to examine as part of what promises to be a long and complex investigation.

"We've only hit the tip of the iceberg as far as a lot of this evidence goes," she told the high security Belmarsh Court in south London.

None of the eight entered a plea and all were ordered held in custody until a court appearance next week.

The charges — filed Tuesday after two weeks of interrogation — for the first time officially linked recent arrests across Britain and Pakistan to the Aug. 1 terrorism alerts surrounding the New York Stock Exchange and Citigroup Inc. headquarters, the International Monetary Fund and the World Bank buildings in Washington, and the Prudential Financial Inc. building in Newark, N.J.

U.S. Attorney General John Ashcroft said Tuesday that federal authorities were considering whether to press charges in the United States against the men and to seek their extradition

During Wednesday's court appearance, prosecutors did not elaborate on the charges. Nothing was said about the connection between the murder conspiracy charge and the charge of conspiring to use chemicals, gas, radioactive materials or explosives, nor how either charge connects to the alleged reconnaissance.

U.S. counterterrorism officials have said that they believe Barot, known by dozens of aliases including Issa al-Britani, was the author of documents, written in fluent English, describing surveillance at U.S. financial buildings during 2000 and 2001. The information was found on computers and in e-mails during the July raids in Pakistan.

Barot was described as a trusted senior Al Qaeda operative sent in early 2001 to do surveillance on possible economic and "Jewish" targets in New York on the orders of Al Qaeda chief Usama bin Laden, according to U.S. interrogations of Khalid Shaikh Mohammed (search), the mastermind of the Sept. 11, 2001, attacks.

Pakistani officials said this week that Barot, known as a veteran of the Islamic militant battle against Indian forces in Kashmir, also traveled in March to a militant hide-out near the Pakistan-Afghan border and met with other terrorist suspects.

The Daily Mail newspaper reported Wednesday that Barot came from a Hindu family that immigrated from Kenya in the 1970s, and that he had converted to Islam in his early 20s.

According to the British police charges, Barot; Mohammed Naveed Bhatti, 24; Abdul Aziz Jalil, 31; Omar Abdul Rehman, 20; Junade Feroze, 28; Zia ul Haq, 25; Qaisar Shaffi, 25; and Nadeem Tarmohammed, 26, were accused of conspiring "with other persons unknown" to commit murder between January 2000 and Aug. 4, 2004.

The eight also were charged with conspiring between those dates to cause a public nuisance by using radioactive materials, toxic gases, chemicals and/or explosives to cause "disruption, fear or injury."

Tarmohammed was also charged with possessing a reconnaissance plan of the Prudential Building. Shaffi was charged with possessing an extract from the "Terrorist's Handbook" on the preparation of chemicals, explosive recipes and other information.

They are scheduled to appear at London's Central Criminal Court on Aug. 25.

A ninth man, Matthew Philip Monks, 32, was charged with possession of a prohibited weapon — an air pistol. He pleaded innocent and was freed on bail pending a trial Sept. 29.

Two other men arrested in the Aug. 3 sweep in Britain were released without charge, and a further two were re-arrested on non-terrorist charges.

The British raids were linked to the July arrest in Pakistan of Mohammed Naeem Noor Khan (search), a computer engineer and Al Qaeda suspect, U.S. and Pakistani officials have said.

Maps, photographs and other details of possible targets in the United States and Britain were found on computers belonging to Khan and to Ahmed Khalfan Ghailani (search), a Tanzanian indicted for his role in the 1998 bombings of U.S. embassies in East Africa, who also was arrested in Pakistan, according to the officials.