BERLIN (AP) — An activist group has apologized to outraged Jewish organizations because of an urn placed outside the German parliament that the activists claim holds the remains of Holocaust victims.

The Center for Political Beauty said late Wednesday they hadn’t intended to hurt the feelings of Holocaust survivors and their descendants when they placed the urn in front of the Reichstag building Monday. They said their intention was to highlight the dangers of far-right extremism by showcasing the remains they claim they found near former Nazi death camps.

On Thursday morning, the transparent urn, about the size of an oil drum, was covered with black plastic wrap.

Jewish groups such as the International Auschwitz Committee and Germany’s Central Council of Jews expressed outrage, saying the installation disturbed the peace of the dead.