Archaeologists have discovered evidence of a brutal mass murder that took place outside Frankfurt some 7,000 years ago during the Stone Age.
The massacre also includes what could be one of the earliest records of torture.
Archaeologists dug up 26 bodies in a mass grave and said the horror of their deaths marked them out.
The remains were first dug up in 2006 in Schoneck-Kilianstadten, about 15 kilometres outside Frankfurt, and now researchers have closely examined the bones.
The legs of the victims seem to have been broken - either just before or just after death.
"Many have injuries, skull fractures caused by typical weapons from the time," said Christian Meyer, who was a PhD student at the University of Mainz when he conducted the research.
The injuries are often on the left of the skull, indicating that they were facing the attacker when they were hit with an adze, 'The Times' reported.
"We can say these people were violently killed, at close quarters. The legs are a new thing, though. This has not been encountered before. The lower leg bones, the tibia and fibula, appear to have been smashed systematically," Meyer said.
"Basic human common sense tells you this has to be either torture or mutilation," Meyer said.
There were no young women among the dead, researchers found.
"This pattern is repeated all over the world at different times. Basically you kill everyone. If you spare someone, it is usually women of reproductive age - you take them with you," Meyer said.
Schoneck-Kilianstadten is not the only site in central Europe of a Stone Age massacre. Archaeologists have also found evidence of such violence in Talheim in Baden-Wurttemberg and in a village near Vienna, according to 'The Local'.
"These three places prove that 7,000 years ago there was already collective violence on a large scale," Meyer said.
The research is published in Proceedings of the National Academy of Sciences.
