The remains of more than 50 people, many of them children, were discovered in a mass grave in Germany, authorities say.Experts suspect the dead in the city of Menden were victims of the Nazis’ so-called euthanasia program, in which disabled people were murdered.

Two more sites are being searched for remains.

The discovery was made by workers from an agency that cares for wartime graves.

Some skulls showed signs that the victims had Down syndrome or other handicaps.

The search for the mass grave followed eyewitness reports that bodies had been transported to the site from a nearby hospital run by Hitler’s doctor, Karl Brandt, who was in charge of carrying out the euthanasia program.

It’s estimated that at least 100,000 handicapped people were murdered between fall 1939 and summer 1941.

Protests by German church leaders brought the euthanasia program publicly to an end, though some parts of the program continued until the end of the war.