THE CHILDREN OF AUSCHWITZ - A SPIT IN THE EYE OF HOLOCAUST DENIERS

Jadwiga Bogucka was 19 during the Warsaw Uprising in August 1944. She and her mother were sent from their house to a camp in Pruszkow and then moved on August 12, 1944, by train to Auschwitz-Birkenau. Photos by Kacper Pempel/Reuters

Maria Stroinska, 82, was 12 when she was sent alone to the Nazi concentration camps at Auschwitz. Imre Varsanyi was 14 and the only member of his family to survive.

Zofia Wareluk was born in the camp, two weeks before thousands of prisoners were liberated on Jan 27, 1945. Her mother was four months pregnant when she was sent there.

They are among the survivors of the Auschwitz death camp in southern Poland, which has come to symbolize the horrors of the Holocaust. Tuesday marks the 70th anniversary of that liberation day.

These portraits capture 20 survivors, many of whom were children and teenagers during their time at the camp.

Jadwiga Bogucka holds a picture of herself from 1944. Photos by Kacper Pempel/Reuters

Concentration camp survivor Jacek Nadolny, 77, was 7 years old during the Warsaw Uprising, when he was sent with his family to Auschwitz-Birkenau by train. In January 1945, his family was moved to a labor camp in Berlin. Photo by Kacper Pempel/Reuters

Jacek Nadolny, 77, who was registered with camp number 192685, holds up a wartime photo of his family, as he poses for a portrait in Warsaw on January 7, 2015. Photo by Kacper Pempel/Reuters

Marian Majerowicz, 88, was 17 when he was sent to Auschwitz-Birkenau. At the camp he was briefly reunited with his father, who told him that his mother and younger brother were both killed in the gas chambers. Majerowicz's father didn't survive the war. Photo by Kacper Pempel/Reuters

Erzsebet Brodt, 89, was 17 years old when she was sent to Auschwitz-Birkenau, along with her family. Remembering the journey to the camp, she said that those who were "sick or about to give birth were forced out and put into one wagon. When the wagon was opened in Auschwitz we saw that everyone was dead inside." Photos by Laszlo Balogh/Reuters

Jerzy Ulatowski, 83, was taken by train to Auschwitz-Birkenau when he was 13 years old. In January 1945, he managed to escape with his family. Photo by Kacper Pempel/Reuters

Lajos Erdelyi, 87, holds a drawing made by a campmate as he poses for a portrait in Budapest on January 13, 2015. Erdelyi was sent to Auschwitz-Birkenau in May 1944 and was later moved to another camp. When he was freed, he weighed less than 70 lbs., but still tried to walk home. He collapsed, and was taken to a hospital by a farmer. Photo by Laszlo Balogh/Reuters

Danuta Bogdaniuk-Bogucka, now 80, was 10 years old when she was sent to Auschwitz-Birkenau with her mother. Bogdaniuk-Bogucka was part of Josef Mengele's medical experiments at Auschwitz. After the war she met her mother again and discovered they had both been at the Ravensbrück camp at the same time without realizing. Photo by Kacper Pempel/Reuters

Stefan Sot, 83, holds a picture of himself taken during the war. Sot was 13 years old during the Warsaw Uprising in August 1944, when he was sent from his home to Pruszkow prior to being transported to Auschwitz-Birkenau. He was later moved to a labor sub-camp, where he worked in a kitchen for S.S. officers. After the war he worked as a typesetter at a printing house. Photos by Kacper Pempel/Reuters

Former Auschwitz concentration camp inmate Laszlo Bernath, 87, credits his survival of Auschwitz to his father being a practical man. He was 15 when they were taken, but his father told him to lie about his age so that they would not be separated. Even while in the camp, Bernath had no idea about the gas chambers. Bernath holds up a picture of his family who were all killed in the concentration camp during World War II. Photos by Laszlo Balogh/Reuters

Elzbieta Sobczynska, 80, holds her father's watch, which was kept by her brother while they were in the camp, as she poses for a portrait in Warsaw January 7, 2015. During the Warsaw Uprising, Sobczynska, then 10, was sent with her mother and brother from their home to Pruszkow and then moved by train to Auschwitz-Birkenau. There they were separated into blocks for women, girls and boys. Sobczynska said that she was robbed of her childhood, and lost the chance to experience a different kind of life. Photos by Kacper Pempel/Reuters

Bogdan Bartnikowski, 82, holds a family photograph as he poses for a portrait in Warsaw December 18, 2014. Bartnikowski was 12 when he and his mother were sent to Auschwitz Birkenau camp. They were moved between camps several times. After the war, Bartnikowski worked as a pilot and then became a journalist and writer. Photos by Kacper Pempel/Reuters

Barbara Doniecka, 80, holds up wartime photo of herself. She was 12 during the Warsaw Uprising when she was sent to the Pruszkow camp. She was then sent by train to Auschwitz-Birkenau. Photos by Kacper Pempel/Reuters

Janos Forgacs, 87, holds a document as he poses for a portrait in Budapest on January 12, 2015. Forgacs recalls that he was in a group transported to a camp in a cattle wagon, the windows sealed with barbed wire. A military officer told them to hand over their belongings because they would not need them anymore. Photo by Laszlo Balogh/Reuters

Maria Stroinska, 82, holds a family photo taken before the war, as she poses for a portrait in Warsaw January 12, 2015. Stroinska was 12 during the Warsaw Uprising when she and her sister were sent from their house to Pruszkow before she went alone to Auschwitz-Birkenau. Photos by Kacper Pempel/Reuters
Henryk Duszyk, 80, was 10 years old in August 1944. He was sent to Auschwitz-Birkenau with his father, brother and stepmother. The family separated, Duszyk only saw his father once more before he was killed at the camp. The remaining three were kept at Auschwitz-Birkenau until the camp was liberated. Photo by Kacper Pempel/Reuters

Janina Reklajtis, 80, holds a photo of herself taken during the war. Reklajtis was 12 when she and her mother were sent to Auschwitz-Birkenau. In January 1945, they were sent to a labor camp in Berlin and kept there until they were liberated. Photo by Kacper Pempel/Reuters

Imre Varsanyi, 86, holds up a photo of fellow survivors during World War II, as he poses for a portrait in Budapest on January 12, 2015. Varsanyi was 14 when he and his family were sent to Auschwitz-Birkenau. He was the only member of his family to survive. After the war, Varsanyi did not talk about Auschwitz for 60 years because he felt ashamed of his survival. Photo by Laszlo Balogh/Reuters

Zofia Wareluk, 70, was born in Auschwitz two weeks before the camp was liberated. Her mother was sent to Auschwitz four months pregnant. Photo by Kacper Pempel/Reuters

Eva Fahidi, 90, poses for a portrait in Budapest on January 12, 2015. She holds a picture of her family members, all of whom were all killed during World War II. Fahidi was 18 in 1944 when she and her family were moved from Debrecen to Auschwitz-Birkenau. Photo by Laszlo Balogh/Reuters

Halina Brzozowska, 82, was 12 when her family were sent to a camp in Pruszkow. She and her 6-year-old sister were moved to Auschwitz-Birkenau. Brzozowska said that it was hard to say what had happened to them, that they were taken from their homes and family, and lost their childhood.