British authorities seized 10 foreigners in early morning raids on Thursday with plans to deport them as a "threat to national security," the government announced. Those detained apparently include a Jordanian-born Islamic cleric accused of having links to both al Qaeda and the terrorists who carried out the Sept. 11, 2001, attacks on New York and the Pentagon.

Charles Clarke, the cabinet secretary who oversees domestic security, did not identify those arrested or the precise reasons they were detained. But the BBC and other news media reported that the group included Abu Qatada, the radical cleric whose taped sermons were found in a Hamburg apartment used by several of the Sept. 11 attackers.

"The circumstances of our national security have changed. It is vital that we act against those who threaten it," Clarke said. He was referring to the train and bus bombings in London on July 7 that killed 52 people along with the four apparent bombers and wounded 700 in the deadliest attack on British soil in half a century.

Officials in the United States and Britain describe Qatada, 44, as an important al Qaeda figure in Europe, and he was once described by a British judge as "a truly dangerous individual at the center in the U.K. of terrorist activities associated with al Qaeda."

Qatada has been convicted in absentia and sentenced to life in prison in Jordan for his role in a plot to bomb tourist sites and an American school. Authorities have also said he has preached to two men held in the United States: convicted shoebomber Richard Reid and Zacarias Moussaoui, who pleaded guilty to conspiring with the Sept. 11 attackers.

The detentions, following raids in London, Leicestershire, Luton and the West Midlands, came days after Prime Minister Tony Blair pledged to deport foreigners who support or incite terrorism. But the detention of Qatada, whose given name is Omar Uthman Abu Omar, is the latest move in the government's legal battles with him since he was arrested in October 2002.

Qatada was taken into custody then on suspicion of terrorism under emergency laws passed by the British government following the Sept. 11 attacks. British officials sought to deport him to Jordan, but British laws forbid sending people to a country where they could face mistreatment or the death penalty.

Instead, the government used the new anti-terrorism laws to hold Qatada and 10 other men indefinitely without charge. The procedure led human rights activists to describe Belmarsh prison, where they were detained, as "Britain's Guantanamo," a reference to the U.S. military detention facility in Cuba.

In December, a panel of British justices ruled that the laws violated human rights and were discriminatory because they applied only to foreigners. Qatada and seven others were released in March. Qatada had served about 2 1/2 years, and some of the others had served more than three years.

At that time, the special immigration appeals judge who freed the men ordered them held under "control orders," a form of house arrest under which they were subject to curfews, electronic tagging, regular searches of their homes and a ban on the use of cell phones and computers.

The detentions on Thursday came a day after Britain and Jordan reached an agreement that included assurances from Jordan that deportees would not be mistreated. British officials were also negotiating to reach similar accords with nine other countries, including Lebanon and Algeria, where several detainees reportedly hold citizenship.

"Following months of diplomatic work we now have good reason to believe that we can get the necessary assurances from the countries to which we will return the deportees so that they will not be subject to torture or ill-treatment," Clarke said in his statement. He said current immigration laws gave him "powers to deport individuals and detain them pending deportation."

Gareth Peirce, a lawyer who represents several of the men detained Thursday, called the detentions "insane and dangerous government at its worse."

"If these men can be safely deported now, why has the Home Office claimed for so many years that that was impossible?" Peirce said. She also charged in a statement that the men have been "deliberately put out of reach of lawyers who represent them." Peirce did not say whether the men would appeal attempts to deport them, and she could not be reached for further comment.

Legal analysts here said it was unclear how judges who overruled the government on its earlier handling of Qatada might view the new attempts to force him out of the country.

Human rights officials expressed concern Thursday about the possibility that the men might be sent to countries where torture is practiced.

"The assurances of known torturers -- many of whom deny the use of torture even when it is widely documented -- are not worth the paper they are written on," said Mike Blakemore, a spokesman for Amnesty International in the United Kingdom. "We have seen no indication of any monitoring to ensure that these promises are honored."

Blakemore said Amnesty believes that the British government must prevent more attacks and bring those responsible for last month's bombings to justice. "But going soft on torture is not the answer to terrorism," he said.

Also Thursday, another radical Islamic cleric, Omar Bakri Mohammed, was detained by authorities in Lebanon, Reuters reported. Bakri, the spiritual leader of a group Blair said he intended to ban, left Britain last weekend. Officials have publicly debated whether Bakri should be allowed back into Britain should he try to return. It was unclear why he was detained in Lebanon.

Ten people, meanwhile, appeared in court Thursday facing charges of withholding information from police investigating the attempted bombings on July 21, the second of last month's two attacks. They were ordered held until a further hearing Nov. 17.

British-based cleric Omar Bakri Mohammed was detained Thursday in Lebanon. British officials have debated whether he should be allowed back.