""Everyone is going to look at Germany during those couple of weeks when we have the championship here," Hans-Jakob Schindler of the Counter Extremism Project told DW.

"That means our adversaries are going to try to do whatever they can to disrupt this."

Fears of a terrorist attack on the Euros have increased since an attack on a concert hall in Moscow earlier this year claimed by an offshoot of the so-called "Islamic State" group left 145 people dead. A threat subsequently published in an IS propaganda magazine suggested the Euros tournament was a target. Still, Schindler said the public nature of that threat makes it less likely that a coordinated attack is planned."