Updated

British authorities continued their crackdown of potential Islamic extremists Thursday, detaining 10 foreigners — chief among them, a Palestinian cleric thought to be Usama bin Laden's (search) spiritual ambassador in Europe.

"The circumstances of our national security have changed, it is vital that we act against those who threaten it," Home Secretary Charles Clarke said in a statement. He gave the 10 foreigners a "notice of intention to deport."

The detainees have five business days to appeal their deportations.

The detentions came a day after Britain signed an extradition agreement with Jordan, where the Palestinian cleric Omar Mahmoud Abu Omar, who is better known as Abu Qatada (search), has been sentenced in absentia to life imprisonment on terror charges.

The Home Office, the organization in Britain in charge of immigration and deportation issues, didn't identify the detainees. But a British government official has confirmed that Abu Qatada was in custody.

The cleric's lawyer, Gareth Peirce, also released a statement condemning the arrests and complaining the individuals had not been allowed to see their attorneys.

The Home Office said the foreigners would be deported once Britain was assured they would not face torture of mistreatment in the countries to which they were being sent.

Prime Minister Tony Blair (search) last week announced measures to deport radical Islamic extremists following the July terrorist attacks on London's transit system.

Abu Qatada was sentenced in Jordan in absentia for his alleged involvement in a series of explosions and terror plots. Copies of his speeches were found in the German apartment of one of the terrorists who brought down four airplanes on Sept. 11, 2001. He also has been described by British officials as bin Laden's "spiritual ambassador in Europe" and allegedly was an inspiration for Sept. 11 hijacker Mohamed Atta (search).

The cleric spent three years in a high security British prison without being charged, under anti-terror powers introduced after the Sept. 11 attacks, but the government did not have enough evidence to keep him in custody. He was released in March after Britain's highest court ruled the legislation breached human rights. Qatada is a Palestinian refugee from Jordan who had been living in Britain since 1993.

As a signatory to the European Convention on Human Rights (search), Britain is not allowed to deport people to a country where they may face torture or death. But the government has been trying to win pledges from approximately 10 countries, including Algeria, Lebanon, Tunisia and Egypt, that deportees would not be mistreated.

An agreement was signed Wednesday with Jordan.

Clarke said in a statement that Britain had received assurances from the countries where it planned to send the detainees that they would not be subjected to torture or ill treatment.

Meanwhile, radical cleric Omar Bakri (search) was arrested in Lebanon by security officials. Bakri left Britain, where he has lived for 20 years, last weekend amid speculation he could face treason charges and flew to Lebanon to see his mother.

The cleric founded the now-disbanded radical Islamic group al-Muhajiroun (search), which came under scrutiny in Britain, particularly after some of its members praised the Sept. 11, 2001, terror attacks.

Several people also appeared in British court Thursday in connection with the failed July 21 bomb attacks.

They included the wife and sister-in-law of Hamdi Issac (search), who is suspected of trying to blow up a subway train.

Issac, also known as Osman Hussain, later was detained in Rome and is being held there on international terrorism charges.

Issac's wife, Yeshiemebet Girma, 29, and her sister Mulumebet Girma, 21, appeared at Bow Street Magistrates' Court to face charges of withholding information from police about Issac's whereabouts. Judge Timothy Workman denied bail and ordered them detained until an appearance at the Central Criminal Court on Nov. 17.

A British judge, meanwhile, ordered Haroon Rashid Aswat (search), a terror suspect sought by U.S. authorities, to remain in custody until Sept. 8.

Aswat, 30, spoke at a preliminary extradition hearing only to confirm his name. He is accused by U.S. authorities of conspiring to set up a camp in Bly, Ore., in 1999-2000 to provide training in weapons, hand-to-hand combat and martial arts for Islamic militants aiming to fight in Afghanistan.

Aswat was deported from Zambia over the weekend and arrested by British police under the U.S. warrant. He has said he would contest the extradition and he denies the U.S. allegations.

Abu Qatada is among 10 foreign terror suspects released in March under a controversial anti-terrorism law in which they can be electronically tagged, kept under curfew, denied the use of telephones or the Internet and barred from meeting outsiders.

Among the eight other detainees due in court, three are also charged with assisting a person in evading arrest.

The three main suspects in the failed July 21 bomb attacks who are in British custody appeared in court earlier this week.

Muktar Said Ibrahim (search), 27, Ramzi Mohammed (search), 23, and Yassin Hassan Omar (search), 24, were ordered to remain in custody until Nov. 14 on charges of attempted murder, conspiracy to murder, possessing or making explosives and conspiracy to use explosives on July 21. They face life in prison if convicted.

So far, British police have not charged anyone in connection with the July 7 bombings, which killed 56 people, including the four attackers.

Britain's Immigration Service on Thursday detained the 10 foreigners in operations in London and the West Midlands, Bedfordshire and Leicestershire regions.

A spokesman for London's Metropolitan Police said officers helped the Immigration Service operation at seven addresses in the capital. Immigration officials detained several individuals, but no arrests were made, the spokesman said. A spokeswoman for West Midlands Police refused to comment on the case.

The Associated Press contributed to this report.