LONDON, Feb.16 (Xinhuanet) -- Britain's chief anti-terrorist police officer on Thursday warned that the war against al-Qaida could last 50 years.

    Peter Clarke, Deputy Assistant Commissioner of Scotland Yard, made the remarks at a conference in London, Sky news reported.

    Clarke called for a new national structure of organizations to police terrorism, as well as changes to the rules over what evidence jurors are allowed to hear in court.

    "Currently, London has the only substantial resource dedicated to the investigation of terrorism. The events of last July showed this is no longer appropriate. We need some form of national structure which still draws on traditional local links," Clarke told the conference.

    Expecting the al-Qaida threat to be under control within five to 10 years was "hopelessly optimistic," he told the conference organized by the Royal United Services Institute.

    Clarke noted that the use of the controversial anti-terror stop-and-search powers should be tightened to avoid alienating ethnic minorities.

    He also mentioned that more than 60 defendants are currently awaiting trial on terrorist charges in Britain, which is an "unprecedented level." Enditem