A man attacked local police officers in the city of Mulhouse shouting "Allahu Akbar" ("God is greatest") on Saturday afternoon, the PNAT prosecutor's office said in a statement.
A knife attack in eastern France has killed one person and injured several others in an “act of Islamist terrorism,” French president Emmanuel Macron has said.
"It is without any doubt an act of Islamist terrorism," Macron told reporters on the sidelines of the annual French farm show, adding that the interior minister was on his way to Mulhouse.
A passer-by was killed trying to intervene, while three police officers were injured, the prosecutor's office added.
A 37-year-old Algerian man was arrested, the prosecutor's office said.