Wildfires burning south of Berlin have forced the evacuation of three villages as the flames continue to detonate grenades and other rusting munitions left behind from World War II, slowing efforts by firefighters to get an upper hand on the fast-moving blazes that have pushed smoke and ash all the way to the country’s border with Poland.

The fires broke out in the midst of a record-breaking dry summer and quickly spread across an area the size of about 500 soccer fields in the normally leafy green forests about 30 miles southwest of Berlin.