BEIJING — A man in northern China killed four members of a family, including a 7-year-old boy, before committing suicide in an apparent feud between former in-laws, China's official news agency said Sunday.

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, the Xinhua News Agency reported. Zhao then killed Zan and Zan's wife, daughter-in-law and grandson with a hammer and kitchen knife he brought with him, the report said.

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

The news agency said the families had feuded after their children's divorce, but gave no other details about the incident, which took place in the city of Botou in Hebei province.