Six people have been fatally shot at a centre for mothers and children by a suspect who was in a custody dispute over his baby daughter, German police say.

The victims - four women and two men - were all staff members at the facility in the northern city of Stade, near Hamburg. A number of other people were also wounded.

The three-month-old baby and her mother were in the office at the time but were not harmed, officials said.

Three people, including the suspected gunman, have been detained by police, and officials said there was no further threat to the public.

The shooting appeared to have been "committed for family reasons", Lower Saxony's Interior Minister Daniela Behrens told reporters late on Monday.

She called it "an act of violence carried out in an extremely cold-blooded manner, with no political or economic motives".

Shots were first reported at around 12:10 local time (10:10 GMT), according to local police, which later confirmed "homicides involving multiple victims" had occurred at a "youth welfare facility" on Dankerstrasse and told the public to avoid the area.

The women and one man were shot dead inside the facility, police said, and a sixth person later died of their injuries in hospital. All the victims were adults.

The suspected gunman was a 45-year-old Turkish national born in Germany and living in Hanover, Lueneburg police chief Kathrin Schuol said.

He had an appointment at the centre on Monday "with many of the victims" to discuss the custody of his daughter, Schuol added.

She said he was known to police "in relation to threats" but had not been considered "as a particularly violent individual". He did not have a firearms licence.

The suspect initially fled the scene in a car driven by a woman, Schuol said.

One eyewitness told news outlet Focus Online that police shouted "stop where you are" at the man and woman and then fired repeatedly at the vehicle.

Footage published by Bild newspaper showed police at a roadblock on a nearby country road stopping a Mercedes with a blown-out tyre.

Armed officers are seen in the clip telling the occupants to get out and detaining them as they lie face down in the road.

Large numbers of police and emergency personnel have been seen to the area.

Children who were at a nearby daycare and primary school at the time of the shooting have since been collected by their parents, a city spokesperson said.

Stade is located about 30km (19 miles) west of Hamburg and has a population of about 50,000 people.