A newly-elected mayor in western Germany has been stabbed and left critically injured near her home, police say.

Iris Stalzer, 57, is a member of the centre-left Social Democratic party (SPD) and became the mayor of Herdecke in the North-Rhine Westphalia state in September.

Local police say a major operation is under way in the small town. Investigators say all avenues are being explores, but they are not ruling out a family connection.

Chancellor Friedrich Merz condemned what he called “a heinous act”, adding: “We fear for the life of the mayor-elect, Iris Stalzer, and hope for a full recovery.”

The SPD said its party members were deeply shocked by the attack.

Officials say Stalzer’s two adopted children – a daughter, 17, and a 15-year-old son – made an emergency call to authorities at midday local time (11:00 BST).

The children were later taken away for questioning and forensic investigation. A reporter at the scene observed a teenager getting into a police patrol car.

This summer there was an incident of domestic violence in the family, which was recorded by the police, security sources said.