A knife-wielding suspect killed a man and injured five police officers Saturday in France in an attack that President Emmanuel Macron called an act of terrorism.

The attack occurred in the city of Mulhouse in eastern France near the German border and left two of the officers seriously wounded.

A 69-year-old man who intervened to help the officers died from stab wounds, authorities said. The attacker shouted “Allahu Akbar.”

Macron said the knife attack was “without any doubt an act of Islamist terrorism.”

The attacker, an Algerian male, was on a terror prevention watchlist and under judicial supervision, according to the anti-terrorism prosecution office.