Chancellor Angela Merkel condemned the "poison" of racism Thursday after a shooter with suspected far-right beliefs killed nine people at a shisha bar and a cafe in the German city of Hanau.
The suspect, identified as 43-year-old German Tobias R., was found dead at his home following an hours-long manhunt.
The body of his 72-year-old mother was also found at the flat in what appeared to be a murder-suicide.
Federal counter-terror prosecutors investigating the case said they saw "a xenophobic motive" behind the shootings, the latest deadly attack blamed on the far right in Germany.
"Racism is a poison, hatred is a poison and this poison exists in our society and it is already to blame for far too many crimes," Merkel said in Berlin.
The suspect left behind online a "manifesto" and video material that suggested a terror attack motivated by "a hostile attitude to foreigners", said Peter Beuth, the interior minister of the state of Hesse.
Among the dead were "several victims of Kurdish origin", the Kon-Med association of Kurds in Germany said in a statement, adding that it was "furious" that authorities weren't doing more to combat rising extremism.
*Tears and anger *
The rampage started at around 10:00 pm (2100 GMT) on Wednesday at a shisha bar in the Heumarkt area of central Hanau, a city some 20 kilometers east of Frankfurt.
The gunman reportedly rang the doorbell and shot at people in the smoking section, mass-market daily Bild said.
He then fled the scene by car before opening fire at the "Arena Bar & Cafe", with witnesses reporting hearing a dozen shots.
A total of nine people were killed, police said. Several others were injured, including one who is in serious condition.
The bloodshed plunged Germany into mourning, and rallies are scheduled in Berlin, Hanau and other cities on Thursday to honor the victims.
Relatives and friends of the victims gathered at the Arena bar around midday Thursday, an AFP reporter said, embracing one another in tears.
Police hurried to cover up the address of the perpetrator's website with a blue plastic sheet after it was spray-painted on the wall of a nearby building.
"I couldn't be any more upset," said Inge Bank, 82, who lives near the bar.
"We have to nip it in the bud if the Nazi party is coming back," Bank said, adding that she had lived through World War II and seen her mother imprisoned in a concentration camp.
*'Same pattern' *
The bar shootings sparked a massive manhunt, with armed officers fanning out across the city and police helicopters roaming the night sky.
Hesse interior minister Beuth said witness reports helped track the suspect's vehicle back to his home.
Special forces then stormed the suspect's apartment where they found him and his mother dead, killed by gunshot.
In a rambling 24-page document seen by AFP, the alleged gunman wrote that people from over two dozen countries should be "destroyed".
He also said he had never been with a woman, which he blamed on being "watched" by unspecified secret services.
King's College London counter-terrorism expert Peter Neumann tweeted of the text that it contained "various, but mostly extreme right views, with a do-it-yourself ideology cobbled together out of parts found on the internet".
"The pattern is clear, and not at all new," he added.
Neumann described the suspect as "an incel", short for someone who is "involuntarily celibate".
Several "incels" have been linked to violent attacks, including a man in Toronto who stands accused of killing 10 people by ploughing a van into pedestrians in 2018.
Leaders were quick to condemn the killings.
German President Frank-Walter Steinmeier echoed Merkel in denouncing the "terrorist violence" in Hanau.
"I stand with all those who are threatened by racist hatred. You are not alone," he said.
European Commission President Ursula von der Leyen, a former German government minister, said she was "deeply shocked by the tragedy".
French President Emmanuel Macron tweeted that he supported Merkel "in the fight for our values and the protection of our democracies".
Merkel pledged to fight back against "all those who try to divide Germany".
She cited the murders carried out by the neo-Nazi "NSU" cell between 2000-2007 as well as last June's killing of pro-migrant politician Walter Luebcke, and the deadly anti-Semitic attack in Halle in October as examples of the threat posed by the far right.
German police have identified around 50 extreme right adherents as "dangerous" individuals capable of carrying out a violent attack.
Last Friday, they arrested 12 members of a German extreme right group believed to have been plotting "shocking" large-scale attacks on mosques, similar to the ones carried out in New Zealand last year.