An emergency police operation today resulted in the detention of many of the leaders of a shadowy, underground organization known as science fiction fandom. The arrests were made under the Prevention of Terrorism Act.

Speaking at a hastily convened press conference outside 10 Downing Street, Prime Minister David Cameron revealed that the organization had been under surveillance for some time.

“We already knew that they were behind the so-called ‘zombie flash mob’ anarchist attack that we foiled on the day of the Royal Wedding. The whole thing was inspired by science fiction novels, and many of the participants were hard core fans,” said the Prime Minister.

“This morning intelligence officers working for the Metropolitan Police uncovered reliable information linking science fiction to al-Qaida. Further investigation revealed a sister organization amongst UK science fiction fans, also known as The Foundation. Their leaders have been taken into custody.”

Amongst the people netted in the anti-terrorist swoop were David Langford, the aging, reclusive leader of UK fandom who regularly railed against the Establishment in his revolutionary pamphlet, Ansible. Mr. Langford was discovered to have large quantities of munitions in his possession.

Many UK science fiction fans are believed to have been radicalized by the Canadian Anarchist preacher, Cory Doctorow, who moved to London a few years ago and has been disseminating anti-government sermons through left-wing newspapers such as The Guardian and Locus (a science fiction magazine based near the notorious Communist enclave of Berkeley, California).

Members of a rival fan organization, the British Science Fiction Association, have quickly declared loyalty to the Crown. However, police sources revealed that they are also under investigation after a recent gathering of the group bestowed honors on a writer called Ian McDonald who lives in Belfast and whom officers therefore believe to have links to the IRA.

The CIA has submitted a request for the extradition of British comics writer, Paul Cornell, who is under investigation for un-American activities involving Superman.

While most of the leaders of this dangerous group are now in custody, some are believed to be in hiding or to have fled the country. Warrants have been issued for the arrest of China Mièville, Ken MacLeod and Tom Hunter, though sources noted that Hunter is suspected to be a pseudonym used by several terrorists due to the sheer volume of his Twitter activity.

Deputy Prime Minister, Nick Clegg, was unable to shed any light on the affair. Asked for a comment, he said, “David won’t tell me anything. He says I’m a security risk because I watch Doctor Who.”