The police said on Twitter that the shooting occurred at a church in the Gross Borstel district, where several people were killed and a number of others injured.
“We found a lifeless person in the community center in #Gross Borstel who we assume could be a perpetrator. In order to rule out the involvement of other perpetrators, we carry out checks and search extensively,” the police said.
According to the Bild daily, the gunman killed at least six people and wounded eight others at the Jehovah's Witness center.
Authorities have not indicated a motive for the shooting but said investigations are running at full speed.