Six people were killed in Germany early Sunday in a head-on high-speed crash between a minivan and a car that was driving the wrong way along a fog-shrouded highway, police said. A woman who stopped at the crash site hoping to find survivors and give first aid was hit by another car and severely injured. The crash took place near the southwestern city of Offenburg, dpa reported. Police said a 20-year-old man had sped the wrong way along the A5 highway and smashed into the van carrying five people moments after a radio alert had warned of what in German is called a "ghost driver". Emergency services said clearing the accident site, strewn with car wreckage and body parts, would likely take all day. The German motorists association ADAC reports about 2,800 "ghost driver" cases a year, 2,000 of them on Germany's autobahn highways which famously have no speed limit. Many cases are blamed on poor signage on exit ramps or driver fatigue, alcohol or drug use, but some cases are suicide attempts.