A solemn commemoration ceremony was held on the site of the former extermination camp, where some 1.1 million people, most of them Jews, were murdered by German Nazi forces between 1940 and 1945. Some 200 survivors of the camp attended, many coming from abroad. Some told of the atrocities they saw and suffered. Auschwitz was liberated by the Soviet army on January 27, 1945.

German President Frank-Walter Steinmeier was among those attending Monday's ceremony, accompanied by his wife, Elke Büdenbender. The gate to the camp seen behind him bears the words "Arbeit macht frei" ("Work sets you free") — words that must have seemed like the bitterest mockery to those imprisoned at the camp.

Steinmeier laid a wreath at the "Death Wall," a reconstruction of the wall against which thousands of people were shot dead by SS men from 1941 to 1943. Poles, Russians and Roma, Sinti and homosexuals were also among those murdered at the camp under the Nazis' remorseless regime.

The former Nazi concentration camp of Buchenwald near Weimar was also the site of a ceremony for the International Holocaust Remembrance Day on Monday. Buchenwald was one of the first and largest concentration camps in Germany. Prisoners included Jews, Poles, Russians, mentally ill and disabled people, political prisoners and prisoners of war. More than 56,000 people died at the camp.

German Family Minister Franziska Giffey joined school pupils in Berlin to lay flowers on "Stolpersteine" ("stumbling stones"), small brass plaques set in the ground to commemorate individual people deported, persecuted or murdered under the Nazis. The project was initiated by German artist Gunter Demnig in 1992. They are mostly located near the victim's last voluntary place of residency or work

Frida Reizman survived a ghetto in the Belarusian capital, Minsk, that was set up by the Nazis. She lit a candle at a ceremony in Belarus in remembrance those who didn't make it. Some 800,000 Belarusian Jews were murdered by the Nazis. Those in the Minsk ghettos lived in extremely poor conditions and were often forced to work in factories. Many ended up being murdered in concentration camps.

Sweden's neutral status in World War II meant it could help rescue Jews from Norway and Denmark who were facing Nazi persecution. Almost the entire Danish Jewish community also found refuge in Sweden, and many Hungarian Jews were saved as well by diplomat Raoul Wallenberg. But the country did not always have a good record: In the 1930s, its immigration policy was not favorable to Jewish refugees.

When the Nazis occupied Hungary in March 1944, the Jewish population lost their rights, were persecuted, deported and finally murdered. Sheindi Ehrenwald, 14 at the time, took notes about it all, including her deportation and life in the Auschwitz-Birkenau concentration camp — which she wrote at the risk of her life. Almost her entire family was killed by the Nazis.

The photo above, probably taken about 1935, is from a happier time in the lives of the Ehrenwald family, who were merchants and part of the large Jewish community in the town of Galanta near the Austrian border. The man in the foreground is Sheindi's father Lipot (Leopold) Ehrenwald, who died in Auschwitz.

On arrival at Auschwitz-Birkenau, the newcomers who were not immediately sent to their deaths were forced to work. Sheindi was transported to a German weapons factory in Lower Silesia.

Sheindi secretly transferred her handwritten notes to index cards thrown out by the arms factory. She managed to hide and save them for the 14 months before liberation. Today, her diary is a rare testimony to that time.

"Punishment at roll call" is the title of a watercolor by Zofia Rozensztrauch, painted in 1945, that shows the brutality of German guards in the concentration camp. The painting is also on display in the exhibition of Berlin's Deutsches Historisches Museum to mark the liberation of the Auschwitz concentration camp 75 years ago.