Mohammed fled just hours before the raid but his sons and another senior al-Qaeda member were found cowering behind a wardrobe in the apartment. The boys have been held by the Pakistani authorities but this weekend they were flown to America where they will be questioned about their father. CIA interrogators confirmed that the boys were staying at a secret address where they were being encouraged to talk about their father's activities. "We are handling them with kid gloves," said one official. "After all, they are only little children, but we need to know as much about their father's recent activities as possible. We have child psychologists on hand at all times and they are given the best of care." Mohammed, 37, is being held in solitary confinement at the Bagram US military base in Afghanistan. He is being subjected to "stress and duress" interrogation techniques.



He has been told that his sons are being held and is being urged to divulge future attacks against the West and reveal the whereabouts of Osama bin Laden. "He has said very little so far," a CIA official said on Saturday. "He sits in a trance-like state and recites verses from the Koran. But while he may claim to be a devout Muslim, we know he is fond of the Western-style fast life. His sons are important to him. The promise of their release and their return to Pakistan may be the psychological lever we need to break him."

The Kuwaiti-born Mohammed named his older son after Ramzi Yousef, his nephew, who was convicted of masterminding the 1993 attack on New York's World Trade Centre. After the attack, Yousef fled to the Philippines with his uncle. When bomb-making chemicals set fire to their Manila apartment, Yousef fled to Pakistan, where he was captured in an Islamabad hotel room in 1995. Mohammed was in the next room and, audaciously, gave an account of the arrest to a reporter. By the time Pakistani authorities found out his identity he had fled the country.

He was eventually arrested on March 1 in Rawalpindi, near the home of Pakistan's President Pervez Musharraf. Among the items found was a photograph of a smiling Mohammed with his arms around his two sons. Known as "The Engineer", he is suspected of masterminding the Bali bombings and slashing the throat of American reporter Daniel Pearl in Pakistan in January last year. Little is known of his sons' mother, who is thought to be Pakistani. "All we know is that she is the sister of an al-Qaeda member that Khalid Sheikh Mohammed met at a Pakistan college, the University of Dawa al Jihad, in the late 1980s," a source said.

- Sunday Telegraph