German investigators say they can confirm evidence to link the murders of 10 people to far-right extremists.
Over the past seven years eight Turks and one Greek, all of them food vendors, have been shot in the face while at work, most on small kebab stalls.
The tenth victim was a policewoman shot in 2007.
Last week two men were found dead during the search of a burnt-out house and caravan in the east German town of Zwickau. Two handguns believed to have been used in the murders were discovered. A woman at the scene was arrested.
All three are known to have had previous links to far-right groups.
German Justice Minister Sabine Leutheusser-Schnarrenberger said: “What has been reported so far is alarming. We now need a comprehensive explanation and what needs to be the focus is whether or not the suspects belong to a right-wing extremist network.”
Some community representatives think the authorities have been slow to make the link to extremists.
Ken Kolat, Chairman of the Turkish Community in Germany, said: “There is unfortunately no real discussion right now in Germany about racism or racist terror. This discussion has to start immediately.”