Germany pledged on Sunday to compensate families of victims of neo-Nazi killings and hold a memorial service, moving to calm anger over suspicions a far-right cell killed at least 10 people over a decade without being caught.

Government officials pledged at the weekend to get to the bottom of the killings and improve coordination to prevent what Chancellor Angela Merkel called a national disgrace from happening again.

Germany's parliament, chancellery, and presidency agreed to hold a national memorial service.

We all agree that an event should be held, the president of Germany's parliament, Norbert Lammert, told Der Tagesspiegel newspaper in an interview.

As for how the remembrance ceremony should appear, it depends not least on the sensitivities and expectations of the victims' families, he said.

Therefore we are seeking a dialogue with them.

Members of the neo-Nazi cell, called the National Socialist Underground, are suspected of killing at least nine immigrants between 2000 and 2007 -- eight Turks and a Greek -- and a policewoman.

As the group was discovered only by chance when two members apparently committed suicide, fears have risen that security services may have underplayed the threat from the extreme right or have been distracted by unreliable informants.

On Saturday, Interior Minister Hans-Peter Friedrich admitted there had been shortcomings in the police investigations into the killings, which had targeted mostly shopkeepers.

It looks as if some authorities failed miserably, he told a meeting of young conservatives in the southern state of Bavaria.

Some families of the victims have complained that the authorities failed to take seriously their suspicions of racist motives behind the murders.

Justice Minister Sabine Leutheusser-Schnarrenberger said the families would be given compensation.

We owe the victims' families a completely new assessment, she told Welt am Sonntag newspaper, adding she feared the investigations may reveal more hate crime victims.

Even if financial aid cannot undo the suffering, I will attempt to give the victims' families a sign of our solidarity with compensation from my budget, she added.

The first break in the case came early this month when police discovered the bodies of two members of the group -- Uwe Boehnhardt, 34, and Uwe Mundlos, 38 -- after a camping car they had retreated to following a botched bank robbery was burnt.

A third member, 36-year-old Beate Zschaepe, who had shared a house with the two men where murder weapons were later found, turned herself into police and has since been charged with membership of a terrorist organisation.

Late last week, Germany's top prosecutor Harald Range said that investigators suspect two more people may have helped the group, besides another accomplice who had already been taken into custody.

(Writing by Brian Rohan; editing by Elizabeth Piper)