Federal authorities charged three men yesterday with conspiring to blow up major financial institutions on the East Coast, as part of the alleged terror plot discovered last summer that prompted a temporary security lockdown in New York City.

A federal grand jury in the Southern District of New York indicted the men, who are British nationals and have been in British custody, on four counts, charging them with conspiring to use weapons of mass destruction, conspiring to destroy buildings, and providing material support and resources to terrorists.

The indictment unsealed yesterday says Dhiren Barot, 32, Nadeem Tarmohamed, 26, and Qaisar Shaffi, 25, entered the country at various times between August 2000 and April 2001, and it accuses them of conducting surveillance missions on buildings in New York, New Jersey, and Washington.

British authorities arrested the defendants in August after the arrest of a Pakistani computer engineer provided information about the alleged plot. Federal authorities indicated yesterday that they would seek the extradition of the suspects but would wait until their trials are completed in England. The suspects face maximum sentences of life in prison.

The indictment accuses Mr. Barot — a convert to Islam, who also goes by the name of Issa al Britani, and was linked by the September 11 commission to Al Qaeda — of applying to a college in New York as a cover for his trips to New York from England. The indictment said Mr. Barot was accepted for the 2000 and 2001 academic years but did not enroll or attend classes. The indictment did not identify the college.

The director of public information at Mohawk Valley Community College in upstate New York, Robert Lacell, told The New York Sun that Mr. Barot applied and was accepted to the community college but never enrolled or attended classes on campus. The college has campuses in Utica and Rome.

“He made an application several years ago, long before 9/11, and was accepted, but we never heard anything from him after the initial inquiry,” Mr. Lacell said.

The college spokesman said Mr. Barot’s application was treated like other international applications at the time. His enrollment, Mr. Lacell said, was contingent on his ability to obtain a student visa from the American consulate of his home country. Mr. Barot also applied to several other academic institutions in New York State and New Jersey, Mr. Lacell said.

Federal authorities accused the three suspects of using video surveillance to monitor such buildings as the International Monetary Fund and the World Bank headquarters at Washington, the Prudential headquarters at Newark, N.J., and the New York Stock Exchange building and Citigroup Center at Manhattan.

The deputy U.S. attorney general, James Comey — a former U.S. attorney in Manhattan — said in a press conference announcing the charges that the indictment “highlights the nature of the enemy we face” and called the investigation an “example of a success” in America’s war against terrorism.

The New York police commissioner, Raymond Kelly, said yesterday he hoped the indictment would have a “deterrent effect.”

“We know that we are very close to the top of the terrorist target list here in New York,” he said.

The September 11 commission report referred to Mr. Barot as an Al Qaeda operative named Issa al Britani. The report states that Khalid Sheikh Mohammed, the captured terrorist leader believed to be the principal architect of the September 11 attacks, sent Mr. Barot to America in early 2001 to “case potential economic and ‘Jewish’ targets in New York City.” Osama bin Laden ordered the trip, according to the report.

Mr. Barot, who was raised as a Hindu, converted to Islam in his early 20s and left his family home in Kingsbury, Middlesex, for Kashmir, where he became a jihadi fighter and authored a terrorist manual called “The Army of Madina in Kashmir,” according to news accounts.The federal indictment says Mr. Barot served as lead instructor at a jihad training camp in Afghanistan around 1998.

Last August 3, British police arrested Mr. Barot and seven other men and accused them of conspiracy to murder and violating provisions of Britain’s Terrorism Act of 2000, which prohibits the collection of information that is likely to be useful to terrorists.

Mr. Barot and Mr. Tarmohamed were accused of possessing “reconnaissance plans” involving the Prudential building in New Jersey, the New York Stock Exchange, Citigroup headquarters in New York, and the IMF in Washington. British authorities charged that Mr. Shaffi possessed a “terrorist’s handbook containing information on the preparation of chemicals, explosive recipes, and other information about explosives.”

British authorities reportedly picked up key information about the plot from the arrest last July of a Pakistani computer engineer, Mohammad Naeem Noor Khan, who was found to have surveillance documents in his computer files.

Two days before the anti-terrorist raid in England last summer, the Bush administration declared a high-risk threat for the targeted financial institutions. The warning, perhaps the most alarming issued by the government since the September 11 attacks, prompted authorities to take extraordinary measure to protect the institutions. At New York, trucks were temporarily barred from entering bridges and police set up checkpoints and barricades near the affected buildings.

The institutions are still under heavy protection. Concrete barriers surround the Prudential complex, and many of the buildings have tightened the screening of visitors and packages. In November, the Department of Homeland Security lowered the threat level for the institutions.