Germany's new justice minister said Thursday that the right-wing extremist National Socialist Underground (NSU) case has not been solved with all its aspects, calling for a further investigation.

Addressing the German Bundestag in her first speech as minister, Christine Lambrecht said the assassination of Kassel governor Walter Lübcke by a neo-Nazi represents a turning point, adding that the country is under far-right threat to a number of different extents. She also mentioned 21-year-old Halil Yozgat, who had been shot in 2006 in Kassel by the NSU.

Walter Lübcke, of Chancellor Angela Merkel's conservative Christian Democrats, was shot dead in the early hours of June 2 on the terrace of his home near Kassel, 160 kilometers northeast of Frankfurt. A neo-Nazi's arrest in the Kassel politician's murder case has fueled debates in Germany on whether the country has failed to take the rising threat from neo-Nazi terrorism seriously. The murder marks post-war Germany's first killing of a politician by a far-right perpetrator.

Stressing that the inquiry committees need to access the relevant documents to shed light on the NSU murders, Lambrecht said the investigation of the killings is far from over and need to be further investigated. She also criticized judicial authorities, saying that they had suspected the victim's families instead of going after the real perpetrators for years.

The NSU killed eight Turkish immigrants, one Greek citizen and a German police officer between 2000 and 2007, but the murders had long remained unsolved.

The German public first learned of the group's existence and its role in the murders in 2011 when two members – Uwe Mundlos and Uwe Bohnhardt – died after an unsuccessful bank robbery. The group's only surviving member Beate Zschaepe was given a life sentence in July, but families of the victims expressed disappointment with the verdict and said the five-year-long trial left many key questions unanswered. Lawyers representing the families disputed the claim that the NSU was only an "isolated cell" of three far-right extremists, and demanded a deeper investigation into their possible ties to a wider network of far-right extremists in Germany.

Earlier this week, Deputy Foreign Minister Yavuz Selim Kıran also called on German authorities to not remain indifferent against rising racist sentiment targeting the Turkish community, adding that the result of NSU case was far from satisfying for the Turks in the country.

Germany, a country of over 81 million people, has the second-largest Muslim population in Western Europe after France. Among the country's nearly 4.7 million Muslims, 3 million are of Turkish origin. Many Turkish origin Germans are second and third-generation German-born citizens of Turkish descent whose grandparents moved to the country during the 1960s.

This Turkish population, largely descending from the country's "guest workers" who arrived to aid the post-World War II development boom, often complain of racist attacks and a lack of follow-up in police investigations into such incidents.