Chancellor Angela Merkel addressed the Berlin memorial service attended by around 1,200 people, including relatives of the 10 thought to have been killed by a neo-Nazi cell that targeted immigrants.

Merkel said the murders were a scandal for Germany. "We will do everything to solve the murders and to bring the perpetrators to justice," she promised. She also asked for forgiveness from the families of the victims.

"No one can erase the mourning and the loneliness," she said, referring to the years it took for police to make any headway in solving the murders as well as the cases in which relatives were themselves suspects. "We can all show you today, that you are no longer alone with your sadness. We feel with you, we mourn with you."

Watch video 00:22 Angela Merkel's speech at the memorial service

The ceremony was intended to be a show of resolve in the fight against far-right extremism.

Trade unions and employers called for a moment of silence to be observed at noon around the country to commemorate victims of neo-Nazi attacks.

Religious leaders demanded action ahead of the memorial service.

It "must be more than a sign of solidarity and sympathy," the president of the Central Council of Jews, Dieter Graumann, told the daily Neue Osnabrücker Zeitung, adding that concrete steps must follow.

"It is important that one condemns racism, but that is not enough," the head of the Turkish Community in Germany, Kenan Kolat, said, criticizing what he said was the absence of a clear government strategy against racism within society.

The focus of the Berlin memorial service was meant to be the presumed victims of the far-right National Socialist Underground (NSU).

Watch video 00:23 Semiya Simek, victim's daughter, challenges Germany's treatment of foreigners

The neo-Nazi cell was discovered in November, when two of the members were found dead in an apparent suicide pact. A third member turned herself in, but is refusing to cooperate with police.

The NSU is believed to have carried out a series of murders across the country that left eight Turkish-German businesspeople, a Greek man and a police officer dead.

Investigations into the group are ongoing.

ncy/dfm (dpa, AFP, epd)