HANAU, Germany (AP) — A 43-year-old German who posted a rant calling for the “complete extermination” of many “races or cultures in our midst” shot and killed nine people of foreign background, most of them Turkish, in an attack on a hookah bar and other sites in a Frankfurt suburb, authorities said Thursday.

He was later found dead at his home along with his mother, and authorities said they were treating the rampage as an act of domestic terrorism.

The gunman attacked the hookah bar and a neighboring cafe in Hanau around 10 p.m. Wednesday, killing several people, then traveled about 1.5 miles and opened fire again, first on a car and then a sports bar, claiming more victims.

The bloodshed came amid growing concerns about far-right violence in Germany and stepped-up efforts from authorities to crack down on it, including last week's detention of a dozen men on suspicion they were planning attacks against politicians and minorities.

Chancellor Angela Merkel said the shootings exposed the “poison” of racism in Germany, and she pledged to stand up against those who seek to divide the country.

“There is much to indicate that the perpetrator acted out of far-right extremist, racist motives," she said. "Out of hatred for people with other origins, other faiths or a different appearance.”

Hookah lounges are places where people gather to smoke flavored tobacco from Middle Eastern water pipes, and Metin Kan, who knew many of the victims, said it was obvious why the gunman chose the neighborhood.

“Look, a hookah bar there, a gaming parlor there, a doner kebab place there — it's a place frequented by immigrants,” he said. “Why this hatred of foreigners? We all get along here.”

People of Turkish background make up Germany's single largest minority, and Turkey's ambassador said five of the dead were Turkish citizens.

Germany's federal prosecutor, Peter Frank, said that all nine people killed were of foreign backgrounds and that six others were injured, one seriously.

Investigators said it appeared the gunman acted alone, but Frank said authorities are trying to find out whether there were others who knew of or supported the attack. He added that his office is looking into any contacts the killer may have had inside Germany or abroad.

Kadir Kose, who ran over from a cafe he runs nearby after hearing the first shots, said he was shocked at the extent of the violence. While fights or stabbings aren’t unheard of, he said, “this is a whole other level, something we hear about from America.”

Witnesses and surveillance videos of the getaway car led authorities quickly to the gunman's home, said Peter Beuth, interior minister for the state of Hesse. Both the attacker and his 72-year-old mother had gunshot wounds, and the weapon was found on him, Beuth said.

Frank identified the gunman only as Tobias R., in line with German privacy laws, and confirmed he had posted extremist videos and a screed with “confused ideas and far-fetched conspiracy theories” on his website, which has since been taken down. He identified himself on the website as Tobias Rathjen.

In his rambling, 24-page screed, Rathjen claimed to have approached police several times with conspiracy theories. But Beuth said it does not appear the gunman had a criminal record or was on the radar of Germany's domestic intelligence agency.

“We now have ethnic groups, races or cultures in our midst that are destructive in every respect,” Rathjen wrote. He said he envisioned first a “rough cleaning” and then a “fine cleaning” that could halve the world's population.

He wrote: “The following people must be completely exterminated: Morocco, Algeria, Tunisia, Libya, Egypt, Israel, Syria, Jordan, Lebanon, the complete Arabian Peninsula, Turkey, Iraq, Iran, Kazakhstan, Turkmenistan, Usbekistan, India, Pakistan, Afghanistan, Bangladesh, Vietnam, Laos, Cambodia and the Philippines.”

Rathjen also detailed fears that he has been under government surveillance for years and blamed the monitoring for his inability to have a relationship with a woman.

The deadly attack was quickly condemned by many organizations, including the Central Council of Muslims, the Confederation of Kurdish Associations in Germany, and the Central Council of Jews.

"This poison exists in our society and its is responsible for far too many crimes," Merkel said, citing killings committed by a far-right gang known as the NSU, the fatal shooting last year of a regional politician from her party, and a deadly attack on a synagogue in Halle in October.

Turkish President Recep Tayyip Erdogan called it a “heinous attack” and expressed confidence that German authorities "will exert all kinds of effort to shed light on all aspects of this attack.”

The killer had a license to possess a gun, first issued in 2013, local authorities told Germany's dpa news agency. Local media reported he owned three 9 mm pistols.

Guns are strictly regulated in Germany, though some 5.4 million of the country's 83 million people possess them. Owners need to undergo background checks, including showing that they are not mentally ill. The gunman's permit was last checked in 2019, dpa said.

German police were also examining a video he may have posted online several days before the attack in which he detailed a conspiracy theory about child abuse in the U.S., dpa reported. The authenticity of the video couldn't immediately be verified, but the YouTube account was under the same name as the website containing the gunman's screed.

In the video, the speaker warned Americans that “your country is under control of invisible secret societies.” In a slow and deliberate voice in accented English, he said there are “deep underground military bases” in which “they abuse, torture and kill little children.”

He made no reference to the far-right QAnon movement in the U.S., but the message was similar to the fringe group's central, baseless belief that President Donald Trump is under attack from “deep state” enemies and that satanists and cannibals are running a child sex trafficking ring.

In his rant, the gunman made one reference to Trump, writing: “I doubt that Donald Trump knowingly implements my recommendations." He suggested that “mind control” might be at work.

On the website, Rathjen wrote that he was born in Hanau in 1977 and grew up in the city, later training with a bank and earning a business degree in 2007.

Geir Moulson in Berlin, Michael Probst and Christoph Noelting in Hanau, and Suzan Fraser in Ankara contributed to this report. Rising and Jordans reported from Berlin.