11:45 AM PT -- According to a German newspaper, an ambulance packed with explosives was found outside the arena.
A huge soccer game -- Germany vs. Netherlands -- has been cancelled for "security reasons" ... and the stadium is being evacuated.
Officials say they had "concrete" information about a bomb threat.
The two international soccer powerhouses were set to face off at HDI Arena in Hannover, Germany -- but an announcement came over the speaker saying the game was off.
Moments later, a nearby venue was also evacuated -- a music arena -- due to another security concern.