A shooting at a Jehovah's Witnesses hall in the German city of Hamburg killed eight people, apparently including the perpetrator, police said Friday. An unspecified number of other people were wounded, some of them seriously. Police gave the figure on their website. There was still no word on a possible motive for the shooting on Thursday evening that stunned Germany's second-biggest city. German Chancellor Olaf Scholz, a former Hamburg mayor, described the shooting as "a brutal act of violence." Police said during the night that they believe that there was only one shooter, and that that this could be a person who was found dead in the building. Investigators worked through the night to secure evidence. On Friday morning, forensic investigators in protective white suits could still be seen outside the building as a light snow fell. Officers placed yellow cones on the ground and windowsills to mark evidence. Hamburg officials said there would be a news conference Friday afternoon to discuss details. David Semonian, a U.S.-based spokesman for Jehovah's Witnesses, said in an emailed statement early Friday that members "worldwide grieve for the victims of this traumatic event." "The congregation elders in the local area are providing pastoral care for those affected by the event," he wrote. "We understand that the authorities are still investigating the details of this crime. We appreciate the courageous help provided by the police and emergency services." The scene of the shooting was the Jehovah's Witnesses' Kingdom Hall, a boxy three-story building next to an auto repair shop in the Gross Borstel district, a few kilometers (miles) from downtown Hamburg. Police spokesman Holger Vehren said police were alerted to the shooting about 9:15 p.m. and were on the scene quickly. He said that after officers arrived and found people with apparent gunshot wounds on the ground floor, they heard a shot from an upper floor and found a fatally wounded person upstairs who may have been a shooter. He said police did not have to use their firearms. Student Laura Bauch, who lives nearby, said there were around four periods of shooting, German news agency dpa reported. "There were always several shots in these periods, roughly at intervals of 20 seconds to a minute," she said. She said she looked out her window and saw a person running from the ground floor to the second floor of the Jehovah's Witnesses hall. Gregor Miesbach, who lives within sight of the building, was alerted by the sound of shots and filmed a figure entering the building through a window. Shots can then be heard from inside. The figure later apparently emerges from the hall, is seen in the courtyard and then fires more shots inside. Miesbach told German television news agency NonstopNews that he heard at least 25 shots. After police arrived, one last shot followed about five minutes later, he said. His video showed a person firing multiple shots into the building through a first floor window before the lights inside the room went out. Jehovah's Witnesses are part of an international church, founded in the United States in the 19th century and headquartered in Warwick, New York. It claims a worldwide membership of about 8.7 million, with about 170,000 in Germany. Members are known for their evangelistic efforts that include knocking on doors and distributing literature in public squares. The denomination's distinctive practices include a refusal to bear arms, receive blood transfusions, salute a national flag or participate in secular government. ___ Moulson reported from Berlin. Associated Press journalist David Rising contributed to this story from Bangkok.