To make sure they wouldn’t go to Guantanamo for prosecution, the British government specifically sought, and got, "binding commitments" between 2004 and 2008 regarding these five particular men, the official said. The negotiations, done as part of U.S.-U.K. treaty negotiations, made clear they "would only be tried in federal civilian court," he added.

Abu Hamza al Masri is a nom de guerre. He was born Mustafa Kamel Mustafa, according to the Justice Department, and immigrated to the United Kingdom to study engineering in the 1970s. A former nightclub bouncer, Masri gained a following as the imam of the notorious Finsbury Park Mosque in north London before British authorities jailed him in 2006 for inciting murder and racial hatred based on fiery sermons he’d delivered years earlier.

The United States has sought to extradite him since 2004, when a federal grand jury in New York indicted him on 11 charges, including hostage-taking and conspiracy to take hostages. Sixteen tourists were held captive in the 1998 attack in Yemen. Four of them were killed.

Masri also was indicted for “providing material support” to terrorists for allegedly setting up an al Qaida training camp in Bly, Ore., from 1999 to 2000, and for supporting violent jihad in Afghanistan.

Adel Abdel Bary, a 52-year-old Egyptian citizen, and Khaled al-Fawwaz, a 50-year-old Saudi Arabian citizen, face murder and conspiracy charges in connection with the bombings of U.S. embassies in Tanzania and Kenya in August 1998. They were indicted by a federal grand jury in New York in 2000.

British citizens Babar Ahmad, 38, and Syed Talha Ahsan, 33, were indicted in Connecticut in 2004 and 2006 on charges of providing material support to terrorists and conspiracy to kill people overseas. Ahmad also is accused of money laundering.

Carol Rosenberg of The Miami Herald contributed.