Scientists say they have found rare evidence of a prehistoric massacre in Europe after discovering a 7,000-year-old mass grave with skeletal remains from some of the continent's first farmers bearing terrible wounds.

Archaeologists who painstakingly examined the bones of some 26 men, women and children buried in the Stone Age grave site at Schoeneck-Kilianstaedten, near Frankfurt, say they found blunt force marks to the head, arrow wounds and deliberate efforts to smash at least half of the victims' shins — either to stop them from running away or as a grim message to survivors.

"It was either torture or mutilation. We can't say for sure whether the victims were still alive," said Christian Meyer, one of the authors of the study published Monday in the journal Proceedings of the National Academy of Sciences.