The Soviets left thousands of corpses piled up in prison yards, corridors, cells, basements, and NKVD torture chambers, as discovered by the advancing Germans in June–July 1941.
The following is a partial list of prisons and other secret execution places, where mass murder took place; compiled by historian Tadeusz Piotrowski, and others.

In eight pre-war Polish voivodeships, the number of dead was between 32,000–34,000.
The locations in alphabetical order included: Augustów prison: (with 30 bodies); Berezwecz: (with 2000, up to 3000 dead);  Białystok: (with hundreds of victims);  Boryslaw, (dozens); Bóbrka: (9–16); Brzeżany: (over 220); Busk: (about 40); Bystrzyca Nadwornianska, Cherven, Ciechanowiec: (around 10); Czerlany: (180 POWs); Czortków, Dobromil: (400 murdered); Drohobycz: (up to 1000); Dubno: (around 525); Grodno: (under 100); Gródek Jagiellonski: (3); Horodenka, Jaworów: (32);  Kałusz, Kamionka Strumilowa: (about 20); Kołomyja, Komarno, Krzemieniec: (up to 1500); Lida, Lwów (over 12,000 murdered in 3 separate prisons); Łopatyn: (12); Łuck: (up to 4000 bodies); Mikolajów, Minsk: (over 700); Nadworna: (about 80); Oleszyce, Oszmiana: (at least 60); Otynia: (300); Pasieczna, Pińsk: ("dozens to hundreds"); Przemyślany: (up to 1000); Równe: (up to 500); Rudki: (200); Sambor: (at least 200, up to 720); Sarny: (around 90); Sądowa Wisznia: (about 70); Sieniatycze: (15); Skniłów: (200 POWs); Słonim, Stanisławów: (about 2800); Stryj: (at least 100); Szczerzec: (about 30); Tarasowski Las: (about 100); Tarnopol: (up to 1000); Wilejka: (over 700); Wilno: (hundreds); Włodzimierz Wołynski, Wołkowysk: (seven); Wołożyn: (about 100); Wolozynek, Zalesiany, Zaleszczyki, Zborów: (around 8); Złoczów: (up to 750); Zółkiew: (up to 60) and Zydaczów.

It was not only prisoners who were murdered by the NKVD as the Soviets retreated.
Other Soviet crimes include Brzeżany, where Soviet soldiers threw hand grenades into homes, and Czortków, where four priests, three brothers and a tertiary were murdered.
The Soviets left thousands of corpses piled up in prison yards, corridors, cells, basements, and NKVD torture chambers, as discovered by the advancing Germans in June–July 1941. The following is a partial list of prisons and other secret execution places, where mass murder took place; compiled by historian Tadeusz Piotrowski, and others.
In eight pre-war Polish voivodeships, the number of dead was between 32,000–34,000. The locations in alphabetical order included: Augustów prison: (with 30 bodies); Berezwecz: (with 2000, up to 3000 dead);  Białystok: (with hundreds of victims);  Boryslaw, (dozens); Bóbrka: (9–16); Brzeżany: (over 220); Busk: (about 40); Bystrzyca Nadwornianska, Cherven, Ciechanowiec: (around 10); Czerlany: (180 POWs); Czortków, Dobromil: (400 murdered); Drohobycz: (up to 1000); Dubno: (around 525); Grodno: (under 100); Gródek Jagiellonski: (3); Horodenka, Jaworów: (32);  Kałusz, Kamionka Strumilowa: (about 20); Kołomyja, Komarno, Krzemieniec: (up to 1500); Lida, Lwów (over 12,000 murdered in 3 separate prisons); Łopatyn: (12); Łuck: (up to 4000 bodies); Mikolajów, Minsk: (over 700); Nadworna: (about 80); Oleszyce, Oszmiana: (at least 60); Otynia: (300); Pasieczna, Pińsk: ("dozens to hundreds"); Przemyślany: (up to 1000); Równe: (up to 500); Rudki: (200); Sambor: (at least 200, up to 720); Sarny: (around 90); Sądowa Wisznia: (about 70); Sieniatycze: (15); Skniłów: (200 POWs); Słonim, Stanisławów: (about 2800); Stryj: (at least 100); Szczerzec: (about 30); Tarasowski Las: (about 100); Tarnopol: (up to 1000); Wilejka: (over 700); Wilno: (hundreds); Włodzimierz Wołynski, Wołkowysk: (seven); Wołożyn: (about 100); Wolozynek, Zalesiany, Zaleszczyki, Zborów: (around 8); Złoczów: (up to 750); Zółkiew: (up to 60) and Zydaczów.
It was not only prisoners who were murdered by the NKVD as the Soviets retreated. Other Soviet crimes include Brzeżany, where Soviet soldiers threw hand grenades into homes, and Czortków, where four priests, three brothers and a tertiary were murdered.
War crimes in occupied Poland during World War II