Britain foiled five attacks in past year - police

CANBERRA, Sep 19 (Reuters) British police have thwarted five attacks in the past year, London's top counter-terrorism commander said today.

Peter Clarke, the Metropolitan Police's anti-terrorism chief, said he was worried many Britons felt that the threat had passed after last year's London underground blasts and the August arrest of 17 people over a plot to blow up transatlantic airliners.

''I sensed at times that in the UK, almost as if a bubble had burst and to some extent a sense, 'well, it's happened and that's that','' Clarke told a security conference in the Australian capital Canberra.

''Well it's far from it. The level of investigative activity has never been at a higher state,'' he said.

Four British Islamists blew themselves up last year on underground trains and a bus, killing 52 people.

In August, British police said they had foiled a plot to bring down US-bound airliners over the Atlantic.

Clarke said there had been five police operations in the past year -- some still under wraps -- against people with ''clear intentions to launch attacks''.

But the failed airliner plot in particular had stunned authorities, not only because of the scale and organisation, but because most of the 17 people arrested had British ties.

''We'll be alleging that a considerable number of those people were prepared to be suicide bombers, and I suppose we were surprised by the fact that so many people had been recruited within the UK to take part in this attack,'' Clarke said.

REUTERS DKA VV1505