BERLIN, Germany (CNN) -- German Chancellor Angela Merkel on Wednesday called photos of German soldiers in Afghanistan playing with a skull "shocking and disgusting," and Defense Minister Franz Josef Jung said those involved will be dealt with harshly.
One image was published on the cover of the national tabloid Bild, under the words "Schock Fotos."
In the picture, a soldier seems to be slightly smirking as he poses with the skull in his raised right hand. A black banner covers his face.
Other images show the skull displayed like an off-center hood ornament on the front of a jeep. Another picture shows a soldier holding the skull near his exposed penis.
A German army spokesman said a prosecutor was questioning two men -- a soldier and a former soldier -- in the case.
Bild did not say how it obtained the photographs, and provided no proof of their authenticity. It is not clear where the skull came from, the newspaper said.
Germany has about 2,700 soldiers in Afghanistan with the International Security Assistance Force, which the United Nations set up in 2001 after the U.S.-led battle to oust the Taliban regime and rout al Qaeda.
The German soldiers provide security for the government in Kabul and other locations in northern Afghanistan. Soldiers from other nations, including the United States and Canada, patrol elsewhere in the country.
"It is crucial to clarify through a clear and unambiguous reaction that the behavior of German soldiers in Afghanistan is condemnable. There are no excuses," Merkel said in a written statement.
"There is no doubt regarding the pictures that the behavior of German soldiers in Afghanistan damages the reputation of the German Bundeswehr (military), which succeeded in building up a high reputation by being involved in international missions over the last years. The incidence also harms the standing of our country."
Germany's deployment of troops to Afghanistan and other destinations is already a controversial issue at home, where many people believe the country still carries the historical burden of World War II.
Nevertheless, Berlin has expanded its international military role with some 9,000 soldiers in hotspots such as the Balkans, Afghanistan, Congo and off the Lebanese coast.