BEIJING (AP) — China’s state-run news agency says a man killed four members of a family, including a 7-year-old boy, before committing suicide in an apparent feud between former in-laws.

The Xinhua News Agency says the 60-year-old man, identified only by his surname, Zhao, went to the home of a man surnamed Zan, whose daughter had once been married to Zhao’s son, late Saturday evening. It says Zhao then killed Zan and Zan’s wife, daughter-in-law and grandson with a hammer and kitchen knife he brought with him.

Xinhua says Zhao then called home to tell his family he’d obtained vengeance, before killing himself at the scene.

The news agency says the families had feuded after their children’s divorce, but gave no other details about the incident in the Hebei province city of Botou.