Two people have been killed in shooting attacks on a synagogue and a nearby kebab shop in the eastern German city of Halle, with the gunman livestreaming the attack on a video-gaming platform.
Before he began shooting on October 9, the attacker also broadcast an anti-Semitic manifesto online.
German police said one suspect was arrested, but two others fled in a hijacked car.
About 70 to 80 people were inside the house of worship, including 10 Americans, U.S. Ambassador to Germany Richard Grenell told AP. The heavily armed assailant shot at the door of the synagogue but couldn't get inside.
The killings took place on Yom Kippur, the holiest day of the calendar in Judaism, when Jews fast, seeking atonement.
Two people were seriously injured in the attack.
German Interior Minister Horst Seehofer said the authorities must assume that it was an anti-Semitic attack, and said prosecutors believed there may be a right-wing extremist motive.
The gunman posted a video of the attack on the Twitch livestream platform owned by Amazon, the company said.
"We are shocked and saddened by the tragedy that took place in Germany today, and our deepest condolences go out to all those affected," a Twitch spokesperson said in response to a media query.
"Twitch has a zero-tolerance policy against hateful conduct, and any act of violence is taken extremely seriously. We worked with urgency to remove this content and will permanently suspend any accounts found to be posting or reposting content of this abhorrent act."
The livestream platform said that five people watched the "horrific act" live during the 35 minutes of its duration and that approximately 2,200 people viewed it in "the 30 minutes before the video was flagged and removed from Twitch."
The Halle town administration said one shooting occurred in front of the synagogue in the city center and its accompanying cemetery, while a second burst of gunfire targeted a kebab bistro.
German Chancellor Angela Merkel attended an evening vigil at a historic synagogue in central Berlin in honor of the victims.
Israeli Prime Minister Benjamin Netanyahu said the attack was "another manifestation of anti-Semitism in Europe."