Analysis of information sources in references of the Wikipedia article "Σοβιετική εισβολή στην Πολωνία" in Greek language version.
In September, even before the start of the Nazi atrocities that would horrify the world, the Soviets began their own program of systematic individual and mass executions. On the outskirts of Lwów, several hundred policemen were executed at one time. Near Łuniniec, officers and noncommissioned officers of the Frontier Defence Cops together with some policemen, were ordered into barns, taken out and shot ... after December 1939, three hundred Polish priests were killed. And there were many other such incidents.