Six people were shot dead and two others wounded in the town of Rot am See in southwestern Germany on Friday, police said.
Among the dead were the parents of the 26-year-old who was arrested after the attack, regional police chief Reiner Moeller told a news conference. Other victims were believed to be related to the suspect, he added.
"We can't say anything so far about the motive," he said. "Because of the victims and the wounded, we believe it was a family drama, since according to what we know at present all were related to each other."
Moeller said that police received a call from a man at around 12:45 p.m. local time (7:45 a.m. ET). He told them he had killed several people.
As police kept the man on the line, officers arrived at the scene and arrested him, he said. They soon found the bodies of three women and three men, between the ages of 36 and 69.
Another two people were hurt, and one of them has life-threatening injuries, Moeller said. The suspect also threatened two children, aged 12 and 14, he said.
Authorities believe he used a semi-automatic pistol and Moeller said that the suspect had a license to own firearms as a shooting club member.
Rot am See is located about 105 miles northwest of Munich. It is a town of some 5,300 people in a rural area of Baden-Wuerttemberg state.