The British government will deport and ban people who "foment, justify or glorify terrorist violence," the country's top law enforcement official announced Wednesday.

Home Secretary Charles Clarke outlined the new policy, the most detailed explanation to date of proposals announced this month by Prime Minister Tony Blair. Clarke said a list of "unacceptable behaviors" includes the use of Web sites, writing, preaching, publishing or distributing materials that "seek to provoke others to terrorist acts" or "foster hatred."

"Individuals who seek to create fear, distrust and division in order to stir up terrorist activity will not be tolerated by the government or by our communities," Clarke said. His statement detailed measures directly resulting from last month's transit system bombings in London, which killed 56 people, including four presumed bombers, and injured 700.

In a report Wednesday night on the July 7 bombings, BBC said one of the four suicide bombers attempted to call his fellow attackers before his device exploded on a city bus. Hasib Hussain, 18, was unable to contact the other three men because they had already died in three subway attacks, the network said, citing unnamed police sources. Officials theorized that all four bombs were intended to blow up on subway lines, but that Hussain was unable to enter a Northern Line station and exploded his bomb about one hour after the subway explosions, BBC reported.

Meanwhile, the Guardian newspaper, quoting unnamed sources, reported Wednesday that all four bombs were detonated by the individual attackers, contradicting versions that the men could have been tricked into carrying the explosives in backpacks, with the bombs then detonated by remote control.

Human rights activists and others have criticized the new British policy. But public opinion polls have shown overwhelming support for tightening laws against religious extremism, even if that leads to limits on free speech and other civil liberties in a nation with a long tradition of tolerance.

"We recognize the sensitivities around the use of these powers and intend to use them in a measured and targeted way," Clarke said. "These powers are not intended to stifle free speech or legitimate debate about religions or other issues. Britain is rightly proud of its openness and diversity and we must not allow those driven by extremism of any sort to destroy that tradition."

Clarke also said a "database of individuals around the world who have demonstrated these unacceptable behaviors will be developed" and made available to immigration officers monitoring those entering Britain. He did not specify who would compile the list or how extensive it might be.

The statement by Clarke did not refer to any particular religious or ethnic group, but the four presumed bombers were Muslim, as are five men suspected by police in failed bombings two weeks after the first attack. Blair had said earlier that he would ban two radical Islamic organizations from Britain and that he planned to bar Muslim clerics who were "not suitable to preach."

Clarke banned a radical Islamic preacher, Omar Bakri Mohammed, from returning to Britain after he traveled to Lebanon. British authorities have also rounded up 10 men for deportation, including Abu Qatada, a radical Islamic cleric who is said to be closely linked to al Qaeda. Taped sermons by Qatada were found in a Hamburg apartment used by several of those who perpetrated the Sept. 11, 2001, attacks on the World Trade Center and the Pentagon.

"I see in this a war on freedom of speech," Azzam Tamimi, a senior leader of the Muslim Association of Britain, said in a telephone interview.

"Prosecuting people for their speech will not prevent a frustrated, angry young man from committing an act of violence," he said. "They don't do it because someone tells them to. They do it because they have no hope."

Liberty, a human rights group in Britain, said Clarke's statement did not provide assurances that those deported would not face torture in their countries of origin. Rights activists have said some countries including Jordan and Algeria, the home nations of many Muslims in Britain, have records on torture.

Clarke has said that Jordan has signed an agreement not to mistreat deportees and that Britain is working on similar agreements with 10 other nations. Rights officials have said such agreements are not reliable.