US investigators deepened their probe today into the terrorist attack on the United States as officials stepped up efforts to derail more potential attacks and police across Europe questioned a string of suspects.
According to US officials, a new threat comes in the shape of hazardous materials being transported on American roads, lethal cargo that can be transformed into bombs.
"Security is extremely tight on the roads," an official with the American Trucking Association said today, following reports that 20 people had been arrested for fraudulently obtaining licenses to transport hazardous materials.
So far, investigators in the US have arrested or detained 353 people and want to question another 392 in connection with the September 11th attacks, but with no sign they had yet caught any of the principal collaborators.
In Europe, investigators were active in a string of countries, notably Belgium, Britain, France, Holland and Spain.
Spain's interior minister, Mr Mariano Rajoy, said today that Spanish police had dismantled a "terrorist cell" linked to bin Laden's al-Qaeda terror network.
He said the cell comprised six Algerians who were members of the Salafist Group for Preaching and Combat (GSPC), one of the groups named by US President George W. Bush in a financial hit list of terror suspects.
In France, judicial authorities ordered seven suspected Islamic extremists jailed after formally placing them under investigation for terrorism.
French authorities believe the seven suspects are linked to a network in Europe close to bin Laden. The network was allegedly planning to attack US interests, including the US Embassy in Paris and the consulate in the southern city of Marseille.
In Belgium, two people detained last week were held today pending further investigation into the discovery of large amounts of potentially hazardous chemicals in Brussels.
Police link those arrests to the September 13 arrest in Brussels of Tunisian-born Mr Nizar Trabelsi on explosives and weapons possession charges.
Meanwhile, the London Timesreported today that 11 of the 19 hijackers involved in the US strikes had possibly taken part in "a vital planning meeting" for the attacks in Britain before joining comrades in the United States in June.
British police yesterday arrested three men in central England they believe may be linked to anti-US terrorist activities in Europe, though the men are not suspected of being involved in the US strikes.
Meanwhile, Dutch police released one man - a Dutch citizen of Iraqi descent - but said he still remained a suspect in their investigation into an Islamist network.
Three other men - two French nationals and a Dutch man who police believe belong to the same network - remain in detention.
Dutch justice officials have said they have no evidence that those arrested were involved in the attacks on the United States.
In the United States, President Mr George W. Bush is pushing Congress to approve a controversial package of new law-enforcement powers, saying investigators needed a beefed-up arsenal to fight terror.
Some US legislators and human rights watchdogs have warned that such legislation could impinge on civil liberties, especially if it is hastily drafted and approved.
AFP