N-tv television and the Bild newspaper said the accidentoccurred in snowy weather on Thursday morning when around 400 federal police officers were conducting a training exercise on dealing with football violence.
Footage on n-tv showed at least one helicopter on its side on the ground.
More top news
Over 2,000 People's Climate March protests have taken place in 166 countries ahead of a major UN conference on climate change.
On English votes for English laws Ed Miliband is damned if he does and damned if he doesn't.
School fees, pricey private medical care and the fear of interest rate rises mean even those on £200,000 are feeling the pinch.