The attack on Iris Stalzer, 57, mayor-elect of Herdecke near the western city of Dortmund, took place at around noon near her own home, said public broadcaster WDR.

“We fear for her life,” Merz said on X.

The details of the attack or suspected motive were not immediately known, as local police did not answer AFP’s phone calls or issue a statement.

Stalzer of the centre-left Social Democratic Party (SPD) had just been elected mayor of the city in the eastern Ruhr area on Sept 28.

In Berlin, the SPD parliamentary group leader Matthias Miersch said that “a few minutes ago, the newly elected mayor Iris Stalzer was stabbed in Herdecke”.

“Our thoughts are with her and we hope she survives this terrible crime… We cannot comment on the background at this time, but we are more than deeply saddened.”

According to Bild daily, Stalzer was found seriously injured by her son in her apartment.