Britain failed to act on information passed to it by Saudi Arabia which might have helped prevent suicide bombings in London in 2005 that killed 52 people, Saudi's King Abdullah said on Monday.

In an interview with the BBC on the eve of a state visit to Britain, King Abdullah accused London of failing to do enough to combat international terrorism and said al Qaeda continued to pose a major threat.

"We have sent information to Great Britain before the terrorist attacks in Britain but unfortunately no action was taken," he said, speaking through an interpreter. "And it may have been able to maybe avert the tragedy."    

The July 7, 2005 suicide bombings on London's transport system were Britain's most devastating peacetime attack.

A spokesman for Prime Minister Gordon Brown's Downing Street office said no warnings were received before the attacks.

"We made it very clear at the time that no specific warnings were received from any source," he said. "We do have a very close intelligence relationship with the Saudis and cooperation on counter-terrorism is generally very good. We just happen to disagree on this point."

King Abdullah is due to arrive in Britain later on Monday for a state visit.

The Saudi monarch said he thought most countries -- including Britain -- did not view terrorism seriously enough.

"I believe strongly ... that it will take 20 to 30 years to defeat the scourge of terrorism with vigilant effort," he said. "And I strongly urge all countries in the world, including Great Britain, to take the matter of fighting terrorism very, very seriously, and to combat terrorism day and night with robustness and vigilance."  -Reuters