At least six people were killed after a gunman opened fire at a youth welfare facility in northern Germany on Monday.Five people, four women and one man, died at the scene of the shooting in Stade, officials said. A sixth person, also an adult, died later at a hospital.All six were employees of the youth centre or its affiliates, they said.Officials added that several people were wounded, some of them seriously, German news agency dpa reported, but they did not give a specific figure or information on the victims’ identities.According to officials, the shooting may have stemmed from a custody dispute. The suspected shooter was arrested.“The police are investigating the motive and the exact course of events under high pressure,” Daniela Behrens, interior minister for the Lower Saxony region, told a news conference.She added that it was an extremely violent crime committed in cold blood, “apparently in a custody dispute.”Police said the shooting took place at the facility on Dankersstrasse, a street south of the town centre. The facility includes temporary accommodation for pregnant women or young mothers with children.The main suspect was arrested, while two other people were subject to “police measures” on suspicion of involvement, police said in a statement. They did not elaborate.Video footage after the shooting showed a large police presence, along with other emergency service personnel and several ambulances on a residential street.Germany’s gun laws are more restrictive than those in the United States, and mass shootings are rare but not unheard of. Vitali Mertens, who lives across the street from the scene, said he heard gunshots and “the whole area was cordoned off right away.”