Germany on Monday commemorated the 30th anniversary of a racist arson attack which claimed the lives of five members of a Turkish family.
President Frank-Walter Steinmeier described the incident as an act of right-wing terrorism.
Turkey meanwhile said it was concerned by a growing trend of “racism, xenophobia and hatred against Islam” three decades on.
Two women and three girls were killed in the fire in Solingen on the night of May 28, 1993, in the deadliest of a series of racist attacks that marred Germany’s first years after reunification.
The attack on the Genc family home injured several others and caused fear and alarm among people of Turkish descent in Germany, some of whom rushed to buy rope ladders in case of a fire.
The youngest victim, Saime Genc, was four years old. Four arsonists were jailed for murder after an investigation that uncovered links to right-wing extremism.
Mr Steinmeier said the fire had left behind “nightmares, memories and fear” for the survivors, some of whom suffered lasting wounds.
He urged politicians not to play with fire by straying into far-right rhetoric. The 1993 attack came at a time of heated debate over asylum seekers in Germany.
“When politicians push the boundaries between what is sayable and what is unspeakable, they are fanning the flames of violence,” Mr Steinmeier told a commemorative event in Solingen.
Many Muslims and people with Turkish names still experience discrimination in German schools and workplaces, recent studies have found.
Mr Steinmeier urged Germans to show “civic courage” when racist incidents occur.
“What I want is fellow citizens who intervene at a bus stop when a girl is being racially abused or attacked, who do not tolerate it when swastikas are sprayed on the wall of a school,” he said.
“Anyone who truly loves this country does not hate their fellow human beings.”
The Solingen fire came six months after a separate arson attack by neo-Nazis that killed three people with Turkish roots in Moelln.
A more recent spate of attacks included a far-right shooting in Hanau in 2020. Nine people were killed by a gunman who opened fire at two shisha bars.
Authorities recently uncovered what they said were two far-right plots to overthrow Germany's post-war democracy.
The suspects included a former MP, an academic and a minor prince, a far cry from the skinhead hooligans who once symbolised Germany's far right.
Foreign Minister Annalena Baerbock said right-wing extremism “is and remains the greatest danger to our society” in a statement on the Solingen anniversary.
Dignitaries including Mr Steinmeier and Turkish deputy foreign minister Yasin Ekrem Serim paid tribute to Mevlude Genc, the surviving matriarch of the family targeted in 1993, who died last year after campaigning for reconciliation and counter-extremism following the fire.
Mr Serim said the government in Ankara would “decisively maintain its fight” against racism and Islamophobia. About 2.5 million people with Turkish roots live in Germany.
“We observe with concern that racism, xenophobia and hatred against Islam keep rising although 30 years passed since the Solingen tragedy,” he said.
