WARSAW, Poland (AP) — A court in Poland on Monday refused to drop a case against two British teenagers caught stealing from the Nazi Auschwitz death camp and has referred it to a lower court.

Initially, the 17-year-old teenagers from Hertfordshire, in southern England, pleaded guilty to charges of stealing items from the historic site while on a school trip in June and were seeking settlement.

They were allowed to return home. But later their lawyers argued that the case should be thrown out, because the teenagers were not aware that the objects they took from the site of the former camp's warehouses had special historic value.

The objects included part of an old hair-cutting machine, two pieces of reinforced glass from the warehouses and some buttons.

A court in the southern city of Krakow admitted the items were of no special historic value, but ordered a court in Oswiecim, where the former camp is located, to weigh charges of simple theft. The verdict is subject to appeal.

Pawel Sawicki, of the museum's press office, said the authorities of the Auschwitz Museum are considering an appeal in which they would stress that any objects coming from the site are of special value to history and to culture.

Polish courts have handed out suspended prison terms and heavy fines to people convicted of stealing objects from Auschwitz, including to an elderly Israeli couple caught in 2011 and a German teacher caught in 2014.

In the most dramatic theft, the ominous "Arbeit Macht Frei" (Work Makes You Free) sign was stolen from the former death camp's historic gate in 2009. It was found days later, cut into pieces. The Poles who stole it and the Swedish man who instigated them were sentenced to prison.

Between 1940 and 1945 the German Nazis killed more than 1.1 million people in the camp. The victims were mainly European Jews, but also Russian prisoners of war, Poles, Gypsies and others.