BERLIN — One or more people opened fire in a church in the northern German city of Hamburg on Thursday evening, authorities said, and local media reported that several people were killed.

The Hamburg city government said the shooting took place in the Gross Borstel district.

Police previously said on Twitter that a large operation was under way in the next-door Alsterdorf district. The area is a few kilometers (miles) north of the downtown area of Hamburg, which is Germany’s second-biggest city.

The German news agency dpa reported that “several” people were dead and some injured, but didn’t give precise figures.

Further details on what happened weren’t immediately available.