The A5 motorway in Baden-Württemberg was closed in both directions between Offenburg and Lahr and was expected to remain shut for most of the day, while emergency services cleared the wreckage and tried to work out what happened.
Victims' identities are yet to have been released, but police confirmed that six people were killed when four vehicles crashed into each other. Fire fighters managed to pull two survivors from the wreckage, one of whom was seriously injured and the other less so.
A police statement said they had received reports of a car going the wrong way up the motorway before the crash.
“The accident site is covered with wreckage,” a police spokesman said, adding that most of that needed to be cleared before investigators could get an idea of what happened.
This was the third accident killing multiple people in Baden-Württemberg over the last three weeks. At the end of October, a crash near Baden-Baden left a family of four dead. At the beginning of November, a father and his three children died.