Archaeologists examining an ancient mass grave in Croatia believe that those killed may have fallen victim to a sneak attack.
At least 41 corpses were found in the mass grave located in Potočani, Croatia, which is expected to be around 6,200 years old, meaning they died around 4,200BC.
The Institute for Anthropological Research (IAR) in Zagreb, Croatia analysed DNA from 38 of the 41 bodies, which revealed their ages, sex and ancestry.
The other three bodies were not analysed as they did not contain enough genetic material to sequence.
Mario Novak, a researcher at the IAR, also revealed that they found evidence of possible injuries caused by blunt weapons on 13 of the recovered skulls.
He explained: 'We assume that these people were probably kneeling or lying down and were struck from behind.'
'All these injuries were lethal because they don’t show any signs of healing, so their death must have been instantaneous.'
He added that there were 20 males and 21 females, with half of those estimated to have been under 17 years of age at the time of their deaths.
The oldest member of the group killed was estimated to have been about 50 years of age: a generous age for a person living in such dangerous times.
Novak elaborated that the people in this group were 'killed indiscriminately,' as there were members of both sexes, all age groups and several families.
The IAR also revealed that all 38 individuals had a similar ancestry, with 91 per cent of their DNA coming from Anatolian Neolithic people and 9 per cent coming from Western European hunter-gatherers.
If you found this story fascinating, you may wish to read about the discovery of the corpses of three executed nuns from World War II-era Poland, which can be viewed here.