AP reports
It's being held at Hannover stadium. There's no information but it's almost-certainly terror related. It's almost 7:30 pm in Germany so it was a last-minute decision.
France plays England in London today as well.
The world will be on edge for awhile.
Update: Separately, Reuters reports that a passenger on a Boston-bound British Airways aircraft was attempting to enter the cockpit and was restrained.
Update 2: Evidently he tried to force open an exit door on the plane, not the cockpit.
Update 3: The passenger was 'intoxicated' according to reports.
Update 4: Dutch TV says the game was cancelled due to a 'concrete' threat.