Fresh arrest in UK terrorism probe
Link between British, Canadian arrests
British police arrest 8 in anti-terror raid
LONDON, England (CNN) -- A ninth man has been arrested in southeast England as part of a major anti-terrorist operation this week in which police seized half a ton of explosives material.
Meanwhile, CNN has learned there is a link between the arrests in Britain and the arrest Monday of a young Canadian man in Ottawa.
On Thursday evening, British police arrested a 27-year-old man in Crawley, south of London, under the 2000 Terrorism Act.
He was taken to a central London police station for questioning and was being held on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism, Scotland Yard said.
On Tuesday, police arrested eight men, ages 17 to 32, in and around London and found half a ton of ammonium nitrate fertilizer in a self-storage facility in West London.
Ammonium nitrate has been used as an explosive ingredient in terror attacks in Bali, Turkey, Saudi Arabia, Africa and the United States.
Late Wednesday a judge agreed police could have three more days to question the eight.
British police also were combing through computer hard drives seized in Tuesday's raids for clues of possible links to groups or individuals outside of Britain.
Hours before Tuesday's raids, Royal Canadian Mounted Police took into custody Mohammed Momin Khawaja, 24, while he was at his job as a software consultant in Canada's Department of Foreign Affairs.
Police also raided the man's family home in the Ottawa suburb of Orleans.
Officials in both Canada and Britain have declined to comment on any links between the arrests.
But documents presented by the Canadian police allege that Khawaja "knowingly facilitated a terrorist activity" in Ottawa and London, England, between November 10, 2003, and March 29, 2004.
Khawaja's brother Qasim has told reporters his brother traveled to Britain late last year, but that it was to try to meet a woman suitable for marriage. Police are investigating whether he also traveled to Pakistan on that trip.
CNN has confirmed that Khawaja's father, Mahboob Khawaja, 62, was arrested by Saudi authorities shortly after his son was arrested in Ottawa.
Mahboob Khawaja, a social scientist and writer, has been teaching at Yanbu Industrial College in Madinat Yanbu Al-Sinaiyah, Saudi Arabia.
Saudi intelligence sources said the arrest was made at the request of the Canadian government. It was not known what charges, if any, the elder Khawaja might face.
Police in Canada and Britain were exploring any links the men may have had to extremists in Pakistan. Seven of the eight men arrested in Britain on Tuesday are British-born of Pakistani descent. The eighth is a naturalized Briton born in Algeria.
Ansar Khan, whose 18-year-old son Ahmed was among those detained in Britain, has said that his nephew, Omar Khyam, age 22 and also detained Tuesday, traveled to Pakistan in January 2000 after telling his family he was going on a school trip to France.
The family enlisted the help of relatives in Pakistan's military and intelligence services to find Khyam, who was eventually located in a Kashmiri "freedom-fighters" camp and returned to Britain, his uncle said.
The family said that Khyam was attending a computer school at the time of his arrest this week.
Omar Khyam's brother Shujah, age 17, also was detained in Britain Tuesday.
The Khan and Khyam families also said they were approached in recent weeks by a man who identified himself as "Mr. Gould" and said he worked for the British domestic intelligence agency MI5.
After meeting family representatives on several occasions, "Gould" suggested that the young males of the family -- who are now in custody -- should leave Britain.
According to the family, "Gould" said the young men did not represent a threat to national security but had been in contact with people who did represent such a risk.
The family said they had made arrangements for the three -- Ahmed Khan and Omar and Shujah Khyam -- to travel to Pakistan next week.
A spokesman for MI5 denied the claim that one of its officers had contacted the families.