British authorities are attempting to keep watch over thousands of terror suspects. (Hat tip: Tom.)

LONDON (AFP) - British police are currently trying to monitor “thousands” of potential security suspects, the head of the anti-terrorism unit at London’s Metropolitan Police said in an interview to be broadcast Sunday.

In an interview recorded in July, before the arrest of more than two dozen people on suspicion of an alleged plot to blow up US-bound aircraft, Peter Clarke said Britain was facing an increasing threat from homegrown extremists.

He refused to give an exact figure about how many people he said were either directly or indirectly involved in plotting atrocities on British soil but said the number ran into four figures.

“I don’t want to go down the numbers game, I don’t think it’s helpful,” he told a BBC television programme entitled “Al-Qaida — Time to Talk?”

“All I can say is that our knowledge is increasing and certainly in terms of broad description, the numbers of people who we have to be interested in are into the thousands.”

He added: “That includes a whole range of people, not just terrorists, not just attackers, but people who might be tempted to support or encourage or to assist.”