Al-Qa'ida suspects captured after phone chips left electronic trail

Anti-terrorism officials have captured dozens of al-Qa'ida suspects and were able to narrow the hunt for one of the world's most wanted men because of the suspects' use of a specific mobile phone chip, it was revealed yesterday.

Operation Mont Blanc, launched in 2002, tracked down the suspects by following an electronic trail left by the Swiss-made chips. Among the alleged al-Qa'ida members whose whereabouts was narrowed by following that trail was Khalid Sheikh Mohammed, the man often described as the network's operations director.

"They thought these phones protected their anonymity, but they didn't," a senior European-based intelligence official told The New York Times. "This was one of the most effective tools we had to locate al-Qa'ida. The perception of anonymity may have lulled them into a false sense of security.

"We now believe al-Qa'ida has figured out that we were monitoring them through these phones." It had long been suspected that members of the terrorism network were using mobile phones to communicate with each other, regularly changing the phones and the numbers they were using.

But the investigation led by Swiss officials focused on the discovery that the operatives preferred a specific type of chip that carried pre-paid minutes and could be used around the world. The chips, made by Swisscom, were popular with the alleged terrorists because they could buy them without providing personal information.

The investigation gathered momentum after 11 April 2002, when investigators traced a call placed by Christian Ganczarski, a 36-year-old Polish-born German Muslim who the authorities suspected was a member of al-Qa'ida. From Germany, Mr Ganczarski called Mr Mohammed, who was at the time in a safe house in Karachi. Officials said that the two men did not talk during the call but that it was instead intended to alert Mr Mohammed that a suicide bombing mission against a synagogue in Tunisia was under way. A total of 21 people, most of them German tourists, were killed in the blast.

Using electronic surveillance, German authorities traced the call to Mr Mohammed's Swisscom mobile phone, even though they did not know it belonged to him. German police later searched Mr Ganczarski's house and found a log of his many numbers, including one in Pakistan that was eventually traced to Mr Mohammed. Once it was revealed he was in Karachi, the authorities turned to the National Security Agency - America's electronic eavesdropping facility - to help pinpoint him.

Mr Mohammed, said to have planned the terrorist attacks of 11 September 2001, was captured in March 2003. Among his belongings was a personal phone book that contained hundreds of numbers. Tracing those numbers led investigators to as many as 6,000 phone numbers, investigators said.

Authorities say that terrorists have now stopped using the chips. It is believed that communications are instead being carried out using internet phones, e-mail or personal messengers. "They know we are on to them and they keep evolving and using new methods, and we keep finding ways to make life miserable for them," said a senior Saudi official. "In many ways, it's like a cat-and-mouse game." They claim, however, that operation Mont Blanc disrupted at least three planned attacks in Saudi Arabia and Indonesia.

Last January, authorities arrested eight people accused of being members of a Swiss-based al-Qa'ida logistical cell. Some of them are suspected of being involved in attacks last year on a housing compound in Riyadh, which killed 35 people.

A spokesman for Swisscom confirmed that the company had co-operated with the inquiry but declined to comment further. Last year, the Swiss authorities passed a new law making it illegal to buy mobile phone chips without providing personal information.

* Yemen has captured an Egyptian militant with suspected links to al-Qa'ida, the second arrest of a senior militant in the south of the country this week. He is believed to be Imam al-Sherif, founder of the Jihad group.