In Germany police and emergency vehicles are only allowed to use "Sonderrechte" (special privileges) when using both the lights and the sirens. So if they want to pass a red light or go the wrong way in a one way lane they have to use the sirens. Note that this is not technically a legal requirement as the law grants them a general exemption but the administrative regulations make this mandatory.

That said, I have seen police cars go the wrong way using hazard lights instead of the blue lights (and no sirens) so I'm not sure what the actual consequences for not following these regulations are.