The grim discovery was made after builders stumbled upon human remains during work at the site in Mikołajki in the Warmian-Maurian Voivodeship.
A specialist team of body searchers from the Institute of National Remembrance (IPN) made the find in a forested area in the city’s Białołęka district following a tip off from an elderly resident who recalled seeing German troops herding people into the area.
The horror discovery was made at the site of the lesser-known Treblinka I forced labour camp where around 20,000 people were imprisoned of which around 10,000 died from exhaustion, injury or execution.
The people in the 5,000-year-old grave were captured and executed with blows to the head. Using genome-wide analysis, a reconstruction of the grave shows mainly women and children lying close together with their bodies and limbs overlapping.