BERLIN Nine months of surveillance involving some 300 security officials were nearly blown when local police in a small German town pulled over several men for a routine traffic violation.
The men were nervous. Germany's federal police chief Joerg Ziercke said those inside feared the local police might be on to their plan to simultaneously detonate car bombs at discos, pubs and airports across Germany frequented by U.S. citizens.
But, he said, federal and state authorities deliberately kept their local colleagues in the dark. The town's officers had no idea the men were suspected of planning what could have been the biggest terrorist attack in postwar Germany and let them go.
A few days later a sting operation arrested three men at a holiday home in a remote village where they had stored enough chemicals to make the explosive equivalent of 550 kg of TNT.
The story of the foiled bomb plot began on New Year's Eve 2006 when security officials spotted Fritz G., a 28-year-old German from Ulm, who appeared to be scouting out a U.S. military base in the town of Hanau in western Germany.
The officials kept an eye on Fritz, along with companions Daniel S., 21-year-old a German from Saarbruecken, and Adem Y., a 28-year-old Turk with German residency. Adem is a Moslem and both Daniel and Fritz are converts to Islam.
All three are believed to have trained at what German officials describe as training camps for terrorists in Pakistan.
Investigators said they quickly became convinced that the three were planning a terrorist attack and in March asked the Federal Prosecutor's Office to take up the matter.
German authorities said they were taken aback by the determination of the trio to execute their plan, driven by what one police official described as a "hatred of Americans".
They procured 12 vats of 35 percent hydrogen peroxide, a chemical commonly used as a disinfectant in the food industry.
But when properly combined with another chemical it can become a deadly explosive like the kind used in the London public transport bombings in July 2005 which killed 52 people.
The London bombers had 3 to 5 kg of explosives. The trio in Germany could have made more than half a tonne.
Before the sting, security agents rendered the chemicals in the vats harmless, authorities said, preventing the trio from putting the final touches on their car bombs as the sixth anniversary of the September 11, 2001 attacks approached.
The suspected would-be-bombers went to Dortmund and bought detonators. It is not clear if they had chosen final targets.
Police descended on the village of Oberschledorn on Tuesday to seize the three men. One tried to escape. A tussle with a police officer ensued. A single shot was fired. Local residents told the press it was like a scene from an action film.