British authorities will deport seven Algerian men detained in dawn raids on Thursday because they are a threat to national security, officials said. A Home Office (Interior Ministry) source said the seven had been accused of being involved in a 2002 plot to manufacture the deadly poison ricin.
They will be deported because their presence in Britain is "not conducive to the public good for reasons of national security," an interior ministry official said.
Britain is trying to persuade several north African countries, one of which is understood to be Algeria, to guarantee they will not mistreat any of their citizens Britain deports to their homeland.
The authorities did not reveal the identities of those held in the raids in the capital, London, and the city of Manchester in northern England.
In April, Kamel Bourgass, also known as Nadir Habra, was found guilty of conspiracy to commit public nuisance by the use of poisons and/or explosions, but eight alleged conspirators were either cleared or the charges against them were dropped.
The civil rights group Liberty said it would be very concerned if the men were deported to their home country because evidence suggests torture there is endemic.
"Our view is that if people have committed an offence it is much better for them to face trial rather than deportation," the Liberty spokesman said.
The seven were detained by immigration officials backed by police under powers available to the Home Secretary under Britain's Immigration Act, and are being held in prison.
Thursday's detentions, and others carried out in August, follow four suicide bombings in London on July 7, which killed 52 and wounded 700.
The 10 people detained last month under the same legislation include the alleged spiritual leader of al Qaeda in Europe, Jordanian national Abu Qatada.
Abu Qatada is accused by Spanish prosecutors of being an inspiration for those who launched the September 11, 2001, attacks on the United States.
Interior Minister Charles Clarke is due to announce details of new anti-terrorism laws later on Thursday.
The most controversial measure is likely to be a proposal to extend the time police can hold terror suspects without charge from two weeks to three months.
In August the government spelled out plans to deport hard-line Islamists it believes are inciting or glorifying militant attacks, and it has signed agreements with some countries, including Jordan, which have said they will not mistreat citizens deported on those grounds.