An ultimatum from Osama bin Laden to European governments will expire this week, but security officials say they do not see it as an immediate trigger for fresh attacks.
Instead, they believe Islamist militants will try to strike whenever they have the means and the opportunity - irrespective of the declared deadline - and will use bin Laden's warning to the Europeans to justify an attack.
French Interior Minister Dominique de Villepin
In an audiotape broadcast by two Arabic television stations on April 15th, the al-Qaeda leader offered a "truce" to European governments if they pulled out their troops from Iraq and Afghanistan.
"I offer a truce to them (Europe) with a commitment to stop operations against any state which vows to stop attacking Muslims," bin-Laden said in a recording which CIA officials said they believed to be genuine.
He set a three-month deadline, presumed to expire tomorrow. Among European governments, Italy - which has almost 3,000 troops in Iraq - has expressed the loudest public concern.
"We are taking the threat seriously. There is special attention. We have singled out 14,000 sensitive targets being guarded by the forces of law and order," Prime Minister Silvio Berlusconi said this month when asked about the deadline.
Other countries have played down the significance of the deadline, insisting that security levels are already high and do not need stepping up further.
"We have been on maximum alert this whole time ... This is the game that the terrorists play and what we should not do is play their game. Their goal is to divide us. We should not enter into this game," French Interior Minister Dominique de Villepin told reporters during a visit to Spain this week.
In Germany, an Interior Ministry spokesman said: "There are no insights that give us reason to tighten security."