A suspected secret cell of foreign militants, believed to be linked to al-Qa'ida and using British hospitals as cover, are being questioned over the terrorist attacks in London and Glasgow.

Five of the eight people under arrest last night are said to be doctors. Another of those detained is the wife of one of the doctors, who is a medical assistant working for the NHS. The home of a sixth doctor is said to have been searched by police. Late last night an Australian television network reported that a suspect wanted in connection with the attacks had been arrested in Brisbane.

Attention has been focused on a group of nationals from the Middle East, who had not previously attracted the interest of security agencies.

Until now, cases of Islamist terrorism have involved mainly Muslims who were born and brought up in Britain. The alleged arrival of teams from abroad to carry out attacks, their identities unknown to the domestic law agencies, adds another dimension to the terrorist threat being faced in the United Kingdom.

"Doc! Doc! It hurts when I do this!"

"Die, unbeliever!!!" [douses them both with kerosene and lights match]