German police arrested a new suspect Sunday following the discovery of an extremist group believed to have killed 10 people in what the country's top security official called "a new form of far right terrorism."
Police arrested a 37-year-old German on suspicion of belonging to the right-wing extremists, and prosecutors labeled the National Socialist Underground group a terrorist organization.
Prosecutors suspect the group, which was discovered only last week, of having murdered eight people of Turkish origin, one Greek national and a German policewoman over the past decade.
"Now it is all about finding out whether ... more people were involved, whether there's a network, finding out which dimension all this has," Interior Minister Hans-Peter Friedrich told reporters in Berlin.
"It looks like, after all the evidence that we have so far, that we are experiencing a new form of far right terrorism," he said, adding that the case was unusual because the group did not publicly claim responsibility or vaunt its actions within the far right scene.
Chancellor Angela Merkel said on the eve of her party's annual convention in the eastern city of Leipzig the "alarming findings" point to "structures that we have not imagined like this."
"It is shocking," she told public broadcaster ARD. "And it is shameful that something like this happened in our country," she added.
Prosecutors are investigating whether the new suspect, identified only as Holger G. in line with German privacy laws, was directly involved in the group's killings. The man is believed to have helped the group's other three known members by providing them with documents and vehicles, one of which was apparently used in the killing of a police officer, prosecutors said.
Two of the other group members are dead while the third turned herself in to police last week.
The group is suspected of having murdered eight Turks and one Greek in several German cities between September 2000 and April 2006, as well as killing a police officer in the southwestern city of Heilbronn in April 2007.
The nine civilian victims were businessmen _ including a flower wholesaler, a tailor and kebab stall owners _ who were shot at their workplaces, and the mysterious series of killings has become known as "kebab murders."
"The link wasn't made between the killings, that became known as 'kebab murders', and politically motivated violence. It was assumed that it must be about organized crime or possibly racketeering," Friedrich said.
The Interior Minister said he has now ordered a review of all violent crimes since 1998 for cases in which investigators suspected a xenophobic motivation but could not find the perpetrators to check whether some crimes might be linked to the terrorist organization.
The 2007 Heilbronn killing also has long been a mystery. The 22-year-old policewoman was fatally shot in the head in a park and a fellow officer was seriously wounded by gunshots.
Last week, both officers' service weapons were found in a burning mobile home in central Germany where two men were found dead, in what police have said was an apparent suicide. The pistol used in the earlier killings was later found at the men's apartment in the eastern city of Zwickau, which also burned out last week following an explosion.
The two men, identified only as Uwe B. and Uwe M., are believed to have had links to far-right circles at the end of the 1990s _ along with a female acquaintance, identified as Beate Z., who turned herself in to police on Tuesday.
Prosecutors said they found DVDs with a propaganda film that contained information on the killings.
German news weekly Der Spiegel reported the group in the DVDs also claimed responsibility for a 2004 attack in Cologne with a small bomb filled with nails that left 22 people injured, mostly Turks.
Officials say the group has been in hiding since 1998 when they were wanted by police for earlier attacks that did not cause injuries, and the group is believed to have financed its operations since then through bank robberies.
Germany's far right is small, splintered and politically marginalized, but concern flares periodically about violence by extremists against immigrants and others. Germany is home to about 3 million people of Turkish origin.