Source: Pakistan link to UK swoop
LONDON, England (CNN) -- At least one of 12 suspects held on suspicion of being involved in terrorist activities in Britain was arrested as a result of intelligence gathered from the arrest of a Pakistani computer expert, Pakistani intelligence officials tell CNN.
They said during an interrogation of Naeem Noor Khan -- described as an al Qaeda computer expert -- he told them there was a terror network in Britain and he frequently relayed messages from Pakistan to its leader, an important al Qaeda operative.
Pakistani officials said after British authorities received this information, they made their raids. They said the person Khan had identified as the leader was among those arrested.
British police have declined to comment on reports of a link between the arrests and the Pakistani intelligence.
Pakistani intelligence sources said that Khan's father works for Pakistan's state run airlines and over the past four to five years he has obtained five tickets in his son's name for travel between Pakistan and London. It is not known if the tickets were ever used.
Anti-terrorist police in Britain were Wednesday questioning the 12 men following coordinated arrests in a dramatic series of daylight raids.
Police swooped in a planned operation at four locations Tuesday as part of inquiries into what they said was "alleged international terrorism."
Thirteen men, aged between 19 and 32, were seized "on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism" under the Terrorism Act 2000. One was later released.
Journalist Susan Jameson, reporting from London's top-security Paddington Green police station, told CNN it was "a major and concerted operation by police."
The men being questioned Wednesday at Paddington Green by members of Scotland Yard's anti-terrorism branch.
The arrests Tuesday came in north west London, Hertfordshire, Bedfordshire and Lancashire.
Police told CNN that a 13th man arrested Tuesday in north London was "de-arrested shortly afterwards and released without further police action."
Search warrants were being executed at homes in the same areas, and the searches "are expected to take some time to complete," according to Scotland Yard.
The Metropolitan police statement did not disclose the nationalities of the men arrested, nor did it provide details of their alleged terrorist activities.
Police declined to specify the men's nationalities, but the BBC said they were all of South Asian descent and some were thought to be British citizens.
The U.S. is on heightened alert following the discovery of documents in Pakistan which apparently mention potential targets for attack both in the US and Britain.
Police would only say that the investigation leading to the British arrests had been under way for some time.
In a statement Scotland Yard said that the raids were part of a "pre-planned, on-going intelligence-led operation."
The statement added: "Yesterday's operation was part of continuing and extensive inquiries by police and the security services into alleged international terrorism."
The arrests came as Prime Minister Tony Blair came under pressure to spell out the level of the terrorism threat in Britain, as a massive security operation continued in U.S. cities. (Full story)
British TV pictures showed officers in fluorescent jackets searching a gold-colored Mercedes in the first public indication of the wide-ranging raids.
Eyewitnesses in Blackburn told the corporation they had seen the arrests of two young men.
Ruth Lazell lives across the street from where one of Tuesday's raids took place, which she described as a large-scale operation.
"I came to the front window and saw quite a lot of armed police officers with guns pointing at two young Asian lads that were on the floor," Lazell told CNN Wednesday.
"Then some other officers came over with blue plastic suits on, put both suspects' arms into plastic bags. Their feet were then put into plastic bags and they were put in a white suit... and led away to an unmarked police car."
Police will have up to two weeks to hold the men before deciding whether to charge them, but courts grant that permission only a few days at a time.
Suspects arrested in previous anti-terrorism raids have often been released without charge before the two weeks expire.
Critics -- particularly among Muslim groups -- say that indicates police have been too quick to make arrests, a charge they deny.
Three months ago, the UK Home Office said that fewer than one in five of those arrested under the Terrorism Act 2000 had been charged with offences under the legislation.
By the end of June this year, 609 people had been arrested under the Act since September 11 2001, the Home Office said.
The Home Office said 99 of those had been charged with offences under the Act, including 38 who were also charged under other legislation. Of the 99 charged, 15 have been convicted.
The remainder were released without charge, bailed to return, cautioned, charged under other legislation or dealt with under immigration or mental health legislation, the Home Office said.
CNN Producer Syed Mohsin Naqvi contributed to this report.