WARSAW, Poland -- A group of 11 people took off their clothes, killed a sheep and chained themselves together by the main gate of the former Nazi German death camp of Auschwitz before being detained by police, officials said Friday.

A spokesman for the Auschwitz memorial, Bartosz Bartyzel, told The Associated Press their motives were not clear as they briefly stood and then sat down by the notorious “Arbeit Macht Frei” (“Work sets you free”) gate in the southern city of Oswiecim on Friday afternoon.

Auschwitz inmates passed through the gate when brought into the death camp and when led by armed Nazi guards to slave labor sites.

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Bartyzel said museum guards ordered the group to dress and called the police. Visits to the site were temporarily suspended.

A statement by the Auschwitz memorial’s authorities said that “using the symbols of Auschwitz for any manifestations or happenings is reprehensible and outrageous” and “hurts the memory of all victims” of Auschwitz.

A spokeswoman for the local police, Malgorzata Jurecka, said 11 young people - Poles, Belarusians and a German - were detained for questioning on allegations they insulted a memorial site. If convicted, they can face stiff fines.

During World War II, the Nazis killed some 1.1 million people at Auschwitz, mostly Jews, but also Poles, Roma and Russian prisoners of war and others.