Police have arrested a computer programmer and charged him with collecting information that could be used to plan a terrorist attack, Scotland Yard said Wednesday.

Mohammed Abdullah Azam, 32, from Luton, 30 miles north of London, was arrested Sunday and has been charged under the anti-terrorism laws, a Scotland Yard official said on condition of anonymity.

He said Azam had been charged with collecting information "of a kind likely to be useful to a person committing or preparing an act of terrorism, or had in his possession documents or records containing information of that kind."

The official would give no further details about Azam or the case, and said he had no information about whether the suspect was linked to any specific group or organization.

Azam is due to appear at Bow Street Magistrates Court in London on Thursday.

Three other men, two aged 21 and one aged 23, also were arrested Sunday in Luton under the Terrorism Act. They were released Wednesday.

On Sept. 6, David Veness head of Scotland Yard's anti-terrorist squad said there was no known specific threat to Britain and encouraged people to carry on "business as usual."

Speaking as the anniversary of the Sept. 11 terrorist attacks on the United States approached, he said, "We shouldn't underestimate these individuals. An individual is not incapable of causing serious impact and that is something we are alert to. Our intention is to enhance the deterrent," he said.

Security forces and police were better prepared to deal with any terror attacks than they were a year ago and his officers had received advice following Sept. 11 from police in other countries with more experience of suicide bombers, he said then.