(CNN) - An alleged former Nazi camp guard who has lived in the United States since the 1950s is facing possible extradition to Germany following his arrest in Philadelphia, authorities said Wednesday.

Federal authorities are moving to extradite Johann (John) Breyer, an 89-year-old U.S. citizen, who is wanted in Germany for war crimes committed during World War II.

Breyer was arrested in Philadelphia, where he has long lived, on Tuesday. Federal Magistrate Judge Timothy R. Rice on Wednesday ordered him held without bail, pending an extradition hearing in late August.

According to court documents filed in the U.S. District Court for the Eastern District of Pennsylvania, German authorities have charged Breyer with complicity in the murder of over 216,000 European Jews from Hungary, Germany, and Czechoslovakia, who were forcibly deported to the Auschwitz II-Birkenau concentration camp on 158 trains between May and October 1944.