( CNN ) -- A sign synonymous with the Nazi work camps of World War II was stolen overnight from the Auschwitz Concentration Camp memorial in Poland , police said Friday . Police were `` alerted at 5 a.m. local time on Friday by museum guards '' that the infamous sign reading `` Arbeit Macht Frei '' -- `` Work Sets You Free '' in German -- was stolen , according to police spokeswoman Agnieszka Szczygiel . The heavy iron sign `` was removed by being unscrewed on one side and pulled off on the other , '' Szczygiel said . `` It is also believed that this was a planned event and that several people were involved as the sign was at remarkable height . '' Police have launched an investigation . The chairman of Yad Vashem , Israel 's Holocaust museum , called the theft shocking . `` While we do n't yet know exactly who stole the sign , the theft of such a symbolic object is an attack on the memory of the Holocaust , and an escalation from those elements that would like to return us to darker days , '' said Avner Shalev . `` I call on all enlightened forces in the world -- who fight against anti-semitism , racism , xenophobia and the hatred of the other -- to join together to combat these trends , '' he said . More than 1 million people died in the Auschwitz-Birkenau concentration camp complex ; about 90 percent of the victims were Jews . Rabbi Marvin Hier , founder and dean of the Los Angeles-based Simon Wiesenthal Center , called the sign `` the defining symbol of the Holocaust '' and urged authorities to intensify their investigation . `` Everyone knew that this was not a place where work makes you free , but it was the place where millions of men , women , and children were brought for one purpose only -- to be murdered , '' Hier said . `` The audacity and boldness of this crime deserves the full attention of the Polish government . '' The center calls itself one of the largest international Jewish human rights organizations . CNN 's Laura Perez Maestro contributed to this report .
Police are looking for a sign that was stolen from someone . The sign read ` ` What Sets You Free '' or ` ` Albeit Macht ' '' Police believe this was a planned robbery that required several people .