A Turkish man arrested in possession of bomb-making materials in Germany had probably been planning to carry out an attack on the anniversary of September 11th, an official in the German state of Baden-Wuerttemberg has said.
German police arrested the 25-year-old today along with his American girlfried. Officials say they were apparent followers of Osama bin Laden.
Separately, the German prosecutor's office said US authorities had arrested an Afghan-born German from the city of Hamburg, where three September 11 hijackers once lived, on suspicion of planning attacks.
In Germany, the arrested German-born man of Turkish decent was in possession of explosives and chemicals near the tourist city of Heidelberg.
His 23-year-old American girlfriend works as a civilian at a US base supermarket.
"We have evidence that an attack was planned for September 11," said Mr Thomas Schaeuble, interior minister for the southwest state. "He seems to be a follower of Osama bin Laden who is deeply religious and harbours a hatred for Americans and Jews."
He said the attacks would have been aimed against US military installations and sites in the centre of the city.
Security has been tightened across Europe ahead of the first anniversary of the attacks on the United States in which more than 3,000 people died.
The Heidelberg area is home to the US Army Europe headquarters and is a popular destination for American tourists and students studying in Germany.
Mr Schaeuble said police had found shells for five bombs and 287 pounds of chemicals and electrical material. The suspect worked in a chemical factory in the western city of Karlsruhe.
He added that Germany had received help from US officials in uncovering the case.
The state interior minister said it was unclear if the pair were part of a larger international terror group. "One must also consider the possibility of fanatical individuals," Mr Schaeuble said.
The case appears to be the first involving a September 11 anniversary attack.
Meanwhile, the prosecutor's office in Karlsruhe said US officials had arrested an Afghan-born German in New York and said he was being held in Virginia. It said the man travelled from Germany to the United States in mid- July and was arrested in late August.
US officials told their German counterpart there was evidence of possible attacks planned by the 39-year-old man, the office said. German authorities was able to identify him and opened a criminal case on charges of membership in a terrorist organisation.