BERLIN — German authorities say a 38-year-old man is believed to have stabbed to death his ex-girlfriend, her new partner and a three-week old baby before killing himself.

The dpa news agency reported Tuesday that authorities are still investigating what motivated the killing, which occurred either Sunday or Monday.

The bodies of the baby and three adults were found in the eastern city of Jena on Monday.

The incident comes as German authorities planned to release figures Tuesday on the scale of domestic violence in the country.

According to federal police figures published by weekly Der Spiegel on Saturday, about 139,000 people in Germany were abused, threatened or stalked by their current or former partner last year. Women made up four-fifths of the victims, and 147 were killed last year.