Alexander Eisvogel, vice president of Germany's domestic anti-terrorist agency, the Federal Office for Constitutional Protection, told Der Spiegel magazine Sunday the killing spree perpetrated by Anders Breivik in which more than 70 people died could "serve as a blueprint for copycats."
What worries him, he said, is that Breivik's actions -- in which he targeted Norway's Labor Party Prime Minister Jens Stoltenberg and members of the party's youth wing who were attending a summer camp -- were scrupulously planned, something new for Europe's right-wing extremists.
"From a terrorism perspective, his plan was meticulously and painstakingly laid out, and he was careful not to attract the attention of the security authorities in advance," Eisvogel said.
"He had everything listed in diary form in his work. It is this mixture of the attacks and their public, accurately described preparations that present the biggest concern."
Eisvogel also said Breivik's attacks represented an expansion of the targets of anti-Islamic hatred. The attack, he told Der Spiegel, was a "new form of xenophobia. The argument is no longer racist, but culturalist and ideological."
The German anti-terrorism chief said reactions within the country's extreme right wing to the Norway massacre so far were "cautious to negative," citing Breivik's explicit rejection of traditional neo-Nazi groups in Europe, such as the German National Party (NPD).
German Interior Minister Hans-Peter Friedrich also said last week he expected more right-wing attacks in the wake of the Norway mass killings.
Friedrich told a German newspaper there is a hard core of about 1,000 extremely violent neo-Nazis and "nationalist anarchists" who model themselves on left-wing anarchists, the Jewish Telegraphic Agency reported.
"Even if we monitor the scene intensively, it cannot be ruled out that individuals have secretly become radicalized," Friedrich said. "The problem is not the ones we can watch but those who radicalize in hiding."
Germany's intelligence service has said the number of crimes committed by right-wing extremist groups have been quickly rising in the formerly communist areas of eastern Germany.
The Norway attacks came at a time when the eastern state of Saxony-Anhalt was debating whether to again try to ban the far-right NPD.
Holger Stahlknecht, a member of Chancellor Angela Merkel's Christian Democrats and interior minister for Saxony-Anhalt, also invited other states to take part in the action, Deutsche-Welle reported.
"We want to push forward proceedings with the necessary judicial care," Stahlknecht said in Halle, Germany, in April.
The NPD, which has two seats in Germany's 16 state parliaments -- but none at federal level -- is classified by security services as a "threat to the constitutional order," and as such could be vulnerable to a ban through the courts.
A similar attempt to ban the NDP, however, was rejected by German courts in 2003 and some German leaders are hesitant to seek a ban.
Wolfgang Bosbach, who heads the Committee on Internal Affairs in the German Parliament, told the Mitteldeutsche Zeitung the court's rejection of a ban eight years ago makes it unlikely to work this time.