Bungled car bombs in London and Glasgow on the weekend may have been organised by doctors. "We have to face the possibility that the health service has been used to get terrorists into Britain and launch attacks against us," a senior police source told the London Mirror. Investigators believe that a dozen doctors from the Middle East may have been involved. Of eight men under arrest on Tuesday in the UK, six were doctors or medical students.

Of the 240,000 doctors working in the UK, 6,000 originally qualified in the Middle East. Nearly a third of these are from Iraq. The first suspect to be nabbed was neurologist Mohammed Asha, 26, a Jordanian of Palestinian descent.

The health professionals link extended to Australia as well. Police in Brisbane have arrested a young Indian-trained doctor who used to work in Britain as he waited to board a one-way flight to India. Police there are also interviewing five other doctors who had trained in India or Pakistan and used to work in Britain.

Although the notion of doctor terrorists is unsettling, it is hardly unprecedented. Al-Qa'ida's chief strategist, Ayman al Zawahiri, is an Egyptian doctor. Radovan Karad?ic, the president of the Bosnian Serb republic, is a psychiatrist. He is still being sought by the United Nations to stand trial on charges of genocide and crimes against humanity.

"There seems to be some surprise that educated people such as medical professionals could become terrorists," risk consultant Robert Heath, of the University of South Australia, told the Australian newspaper. "People are not born terrorists and extreme behaviour does not depend on education or wealth. You can have extreme beliefs no matter whether you are a doctor, a religious person, or a politician."