Spy operation on alert

Britain's Home Secretary John Reid speaks during a news conference. Picture / Reuters

The biggest surveillance operation in British history is under way this week as the authorities seek to track what the Home Secretary, John Reid, has called "dozens" of terror plots.

While every police force in the country is now involved in investigating the alleged plot to bring down transatlantic airliners, MI5, the main counter-terror agency, is being strained to the limit as it seeks to head off the next threat.

"The one thing we can be sure of is that there will be a 'next one'," said a Whitehall source. "The big question, indeed, is 'Where next?"'

Ten days after the world learned about Operation Overt - the wave of arrests in Britain and Pakistan which is said to have prevented the attack on air travel - airports are returning to something approaching normal.

The 23 suspects are being held in high-security police stations.

A further 17 people - some British, some local citizens - are reported to have been arrested in Pakistan, where intelligence officials fuel speculation about al Qaeda links.

In Britain, although the Home Secretary has spoken of the suspected "main players" being accounted for, and "substantial" material having been found at suspect properties, few other details have been forthcoming.

The national threat assessment, raised to "critical" - its highest level - when Operation Overt was launched, has been lowered one notch to "severe". But behind the scenes there is acute concern.

Security services estimate Britain has about 400 potential terrorists, including a "hard core" of around 50.

Beyond those there may be as many as 800 more extreme Islamist "peripherals" who could become active terrorists at any point, giving the security services further problems in deciding who to follow.

Tensions have arisen in the struggle to secure evidence of the "airliners plot" and prevent future attacks.

American pressure triggered the arrest in Pakistan of Rashid Rauf, the former resident of Birmingham accused of a key role in the plot.

"Britain wanted the Pakistanis to keep him under observation and help gather evidence against him, but they and the Americans have far less concern for due process," said one source.

After Rauf's detention, British sources say, they observed a surge in electronic traffic from Pakistan to Britain, suggesting the conspirators were speeding up their plot.

This forced the authorities to move in much sooner than they wished, which is why the investigation is at such an embryonic stage.

One official said the US Administration wanted to announce Operation Overt before the arrests in Britain had even been completed.

A police source said some senior officers were angry they had to arrest people so early.

- INDEPENDENT