The bodies of five children have been found in a private apartment in the city of Solingen in western Germany, police say.
They gave few initial details about the discovery, with no information about the cause of death.
Emergency services were called to the residential block in the Hasseldelle area of the city on Thursday.
Police are reportedly treating the incident as a criminal act, and are expected to give further details later.
According to unconfirmed reports published on the German news website Bild, the five children were aged from one to eight. A sixth child, reportedly aged 11, was said to have survived.
Few details about the children's parents have been given, although there are unconfirmed reports that the mother, 27, attempted to kill herself at a train station in Düsseldorf.
A local police spokesman told Bild: "We can't say anything about the motive yet. The mother must be interviewed."