A gunman stormed a service at his former Jehovah’s Witness hall in Germany, killing six people before taking his own life after police arrived, authorities in the port city of Hamburg said Friday.

Police gave no motive for Thursday night’s attack. But they acknowledged recently receiving an anonymous tip that claimed the man identified as the shooter showed anger toward Jehovah's Witnesses and might be psychologically unfit to own a gun.

Eight people were wounded, including a woman who was 28 weeks pregnant and lost the baby. Chancellor Olaf Scholz said the death toll could rise.

Officers apparently arrived at the hall while the attack was ongoing and heard one more shot, according to witnesses and authorities. They did not fire their weapons, but officials said their intervention likely prevented further loss of life at the boxy building next to an auto repair shop a few kilometers (miles) from downtown.

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Scholz, a former Hamburg mayor, said the city was “speechless in view of this violence” and “mourning those whose lives were taken so brutally.”

All of the victims were German citizens apart from two wounded women, one with Ugandan citizenship and one with Ukrainian.

Officials said the suspected assailant was a 35-year-old German man identified only as Philipp F., in line with the country's privacy rules. Police said he had left the congregation “voluntarily, but apparently not on good terms,” about a year and a half ago.

A website registered in the name of someone who fits the police description says that he grew up in the Bavarian town of Kempten in “a strict religious evangelical household.”

The website, which is filled with business jargon, also links to a self-published book about “God, Jesus Christ and Satan.”

Philipp F. legally owned a semi-automatic Heckler & Koch Pistole P30 handgun, according to police. He fired more than 100 shots during the attack, and the head of the Hamburg prosecutors office, Ralf Peter Anders, said hundreds more rounds were found in a search of the man’s apartment.

Germany’s gun laws are more restrictive than those in the United States but permissive compared with some European neighbors, and shootings are not unheard of.

Last year, an 18-year-old man opened fire in a packed lecture at Heidelberg University, killing one person and wounding three others before killing himself. In 2020, the nation saw two high-profile shootings, one that killed six people and another that took nine lives.

In the most recent shooting involving a site of worship, a far-right extremist attempted to force his way into a synagogue in Halle on the Jewish holy day of Yom Kippur in 2019. After failing to gain entry, he shot two people to death nearby.

The German government announced plans last year to crack down on gun ownership by suspected extremists and to tighten background checks. Currently, anyone who wants to acquire a firearm must show that they are fit to do so, including by proving that they require a gun. Reasons can include being part of a sports shooting club or being a hunter.

Hamburg Police Chief Ralf Martin Meyer said the man was visited by officers after they received an anonymous tip in January, claiming that he had “particular anger toward religious believers, in particular toward Jehovah’s Witnesses and his former employer.”

Officers said the man was cooperative and found no grounds to take away his weapon, according to Meyer.

“The bottom line is that an anonymous tip in which someone says they’re worried a person might have a psychological illness isn’t in itself a basis for (such) measures,” he said.

Germany’s top security official laid a wreath of flowers outside the hall to commemorate the victims and thanked police before taking questions from reporters.

Asked whether the attack could have been prevented, Interior Minister Nancy Faser said it was necessary to wait for the investigation to conclude, but she acknowledged that changes were needed in the way background checks are conducted and information is exchanged between authorities.

She said a bill now making its way through the legislative process would require gun owners to undergo psychological tests.

On Friday morning, forensic investigators in protective white suits could be seen outside the hall. As a light snow fell, officers placed yellow cones on the ground and windowsills to mark evidence.

A special operations unit that happened to be near the hall arrived just minutes after receiving the first emergency call at 9:04 p.m., Hamburg’s top security official said. The officers were able to separate the gunman from the congregation.

“We can assume that they saved many people’s lives this way,” Hamburg state Interior Minister Andy Grote told reporters.

Upon arrival, officers found people with apparent gunshot wounds on the ground floor and then heard a shot from an upper floor, where they found a fatally wounded person believed to be the shooter, according to police spokesman Holger Vehren.

Gregor Miebach, who lives within sight of the building, heard shots and filmed a figure entering the building through a window. In his footage, 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 through a first floor window before the lights in the room go out.

Miebach told German television news agency NonstopNews that he heard at least 25 shots. After police arrived, one last shot followed, he said.

His mother, Dorte Miebach, said she was shocked by the shooting. “It's really 50 meters (yards) from our house and many people died,” she said. “This is still incomprehensible.”

Jehovah’s Witnesses are part of an international church founded in the United States in the 19th century and headquartered in Warwick, New York. The church 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 practices include a refusal to bear arms, receive blood transfusions, salute a national flag or participate in secular government.

David Semonian, a U.S.-based spokesman for Jehovah’s Witnesses, said in an emailed statement Friday that members “worldwide grieve for the victims of this traumatic event.”