It is "only a matter of time" before a biological, chemical or nuclear terrorist attack is attempted on a Western city, the head of the British military intelligence service said today.
Director-general of MI5 Ms Eliza Manningham-Buller said intelligence suggested that "renegade scientists" had given terrorist groups the information they needed to create such weapons and that they would become more sophisticated.
But she added that conventional bombs and suicide bomb attacks remained their preferred weapons.
"They [al Qaeda] still remain an organisation capable of deadly terrorist attacks," she said.
"The threat from international terrorism is with us for a good long time . . . if this is a war that can be won, it is not going to be won soon. . . . The supply of potential terrorists among extreme elements is unlikely to diminish".
Ms Manningham-Buller was making her first on-the-record speech since taking on her new job in October last year.
She told a conference at the Royal United Services Institutein central London that al-Qaeda was "the first truly global threat". Recent attacks in Riyadh and Casablanca proved it and other groups still posed a "potent threat".
PA