A stark warning that as many as 200 'Osama bin Laden-trained terrorists' were walking the streets of Britain determined to carry out mass attacks was made by Britain's former top police officer less than six months ago. Sir John Stevens - now Lord Stevens - who retired as London Metropolitan Police chief in February, issued the warning as British Prime Minister Tony Blair was trying to push through tough new laws to allow the house arrest of foreigners without charge, against strong opposition. The laws were thought to be needed because an old law passed in the wake of the September 11 attacks had expired. They were finally passed with a caveat that they be reviewed after one year. Law lords had earlier ruled that such powers violated basic rights. Fearing that the laws would be quashed, Sir John told the News of the World: 'This new act must be passed as soon as possible. The main opposition to this bill is from people who simply haven't understood the true horror of the terrorism we face.' 'As you read this, there are at least 100 Osama bin Laden-trained terrorists walking Britain's streets. The number is probably nearer 200: the cunning of al-Qaeda means we cannot be exact. 'But they would all commit devastating terror attacks against us if they could, even those born and brought up here.' In the article, titled 'Forget human rights ... kick out the fanatics', Sir John dismissed human rights arguments, arguing that judges and the government had a greater duty to law-abiding citizens than to 'hardcore fanatics'. 'For the safety of the vast majority, occasionally we will have to accept the infringement of the human rights of high-risk individuals,' he wrote. 'Intelligence proves these fanatics must not walk our streets. They must be locked up - or kicked out of our country.' Sir John added that a terrorist attack was not possible but inevitable, a position later backed up by officials from Britain's spy agency MI5.