German police say one person has been killed and another 11 injured in an explosion at a cafe in the Bavarian city of Ansbach.

Police told the dpa news agency early Monday that it wasn't clear what caused the late Sunday night blast in the city near Nuermberg.

Ansbach police could not immediately be reached for comment but Germany's top-selling Bild newspaper said it was believed to have been a gas explosion.

Dpa reports that an open-air concert nearby with some 2,500 in attendance was shut down as a precaution after the explosion.

Germany is on edge after a deadly rampage at a Munich mall on Friday in which nine people were killed and an ax attack on a train near Wuerzburg last Monday in which five people were wounded.