Six people were killed in a shooting at a youth welfare facility in the northern German town of Stade, police said on Monday.
Two people, a male suspected shooter and his female companion, were arrested.
Police said it was likely a "family tragedy."
There were also injuries, police said, but they did not give a figure.
Police said the shooting took place in the facility on Dankersstrasse, a street south of the town centre.
Police said they were working to establish the background to the shooting and what exactly happened.
Germany's gun laws are more restrictive than those in the United States, and mass shootings are rare but not unheard of.
Stade has about 50,000 inhabitants and is located about 40 kilometers from Hamburg.
Police said a major operation was underway in central Stade but said that there was no danger to the public.
As a precaution, they advised members of the public to stay away from the crime scene while the investigation continues.
"We ask you to leave the area and give it a wide berth for your own safety," they said in a post on X.
This is a developing story, and our journalists are working on further updates.
