Unexploded munitions were hampering efforts by firefighters to tackle a blaze in a national park in northern Germany, local officials said on Wednesday.Old munitions buried in the soil from an abandoned military training ground have forced them to stay at least 1,000 metres (3,300 feet) from the flames, officials from the Mecklenburg Seenplatte district said.“Emergency services cannot actively put out the fire – that is the problem,” district spokesman Marten Schroeder said of the fire in...