Germany's Foreign Ministry says a German citizen is believed to have been kidnapped in Afghanistan.

Ministry spokesman Martin Jaeger told reporters Wednesday that the man has been missing since June 28. Jaeger says the government has set up a crisis unit to investigate his disappearance.

It was unclear why the missing man was in Afghanistan. The ministry says he was not working for the German government, a relief agency or the media.

In March, gunmen killed a German aid worker in Afghanistan during an attack on his vehicle.

About 3,000 Germans are serving with NATO in Afghanistan.

Some information for this report was provided by AFP, AP and Reuters.