WARSAW, Poland (AP) — Poland protested Sunday a mistake in a social media post by the head of the European Commission that wrongly suggested the World War II Auschwitz death camp was Polish.

That post by Ursula von der Leyen on X, formerly Twitter, was later corrected to say that Auschwitz was a Nazi German extermination camp.

In the post, von der Leyen and European Union commissioners pay tribute to victims of the Holocaust to mark International Holocaust Remembrance Day on Saturday. They write and say the names of some of the victims. Added text states their birth and death place and date. In the original post, the Auschwitz camp was described only as “Poland.”

Phone and text messages left Sunday with Christian Wigand, EU Commission spokesman, were not immediately returned.

Foreign Minister Radoslaw Sikorski wrote on X that “When referring to the Nazi extermination camp in Auschwitz, it should be noted that it was established under German occupation.”

He added that “information posted on the European Commission’s social media will be clarified.”

On Saturday, a group of Holocaust survivors and state officials held a modest ceremony at the memorial and museum site of Auschwitz-Birkeanu to mark the 79th anniversary of the camp's liberation by the Soviet troops on Jan. 17, 1945. The day is now dedicated to Holocaust remembrance.

Germany invaded neighboring Poland on Sept. 1, 1939, starting World War II. Beginning in 1940, the Nazis were using old Austrian military barracks in the southern town of Oswiecim as a concentration and death camp for Polish resistance members. In 1942 they added the nearby Birkenau part, with gas chambers and crematoria, as a mass extermination site, mostly of Europe's Jews.

An estimated 1.1 million people, mostly Jews, were killed in Auschwitz-Birkenau until its liberation. During that time, Poland was under brutal German occupation and lost some 6 millions citizens, half of them Jews.

Polish law penalizes anyone wrongly blaming Poles for Nazi Germany’s crimes on Polish soil.