The police spokesperson told the outlet that the house is located on Hasselstrasse, but gave no further details.
According to the Bild newspaper, the grandmother of the kids called the police and told them that her daughter had killed five of her children and ran away with another one of her kids.
The kids reportedly range in age from one to eight.
The newspaper reports that the mother of the children jumped off a platform at the Duesseldorf train station, but survived, although badly injured.