BERLIN (AP) — The Buchenwald concentration camp memorial says that seven trees dedicated to the memory of victims of the Nazi camp in eastern Germany have been chopped down.

The foundation that runs the memorial tweeted on Wednesday that the trees near the site apparently were attacked the previous day. It posted pictures showing the trees severed about halfway up the trunk, and said it was “appalled at the deliberate attack on remembrance.”

The foundation said that it had filed a complaint to police.

One of the trees was dedicated to children killed at Buchenwald and the others to six prisoners at the camp. The trees were part of a project called “1,000 beeches” and were planted on a route outside the actual camp along which prisoners were taken.

The Buchenwald concentration camp was established in 1937. More than 56,000 of the 280,000 inmates held at Buchenwald and its satellite camps were killed by the Nazis or died as a result of hunger, illness or medical experiments before the camp’s liberation on April 11, 1945.