One person has died and two police officers have been seriously injured in a knife attack during a demonstration in eastern France, the local prosecutor has said.
The French president, Emmanuel Macron, said: “It is without any doubt an act of Islamist terrorism.”
Three more officers were lightly wounded when a man attacked local police officers in the city of Mulhouse, shouting “Allahu Akbar”, meaning “God is greatest” in Arabic, on Saturday afternoon, the anti-terror prosecutors unit (PNAT) office said.
A passerby was killed trying to intervene, it said.
The suspected attacker, who has been arrested, is on a terror prevention watchlist, prosecutor Nicolas Heitz told AFP.
The list compiles data from various authorities on people to prevent terrorist radicalisation. It was launched in 2015 after deadly attacks on the offices of satirical magazine Charlie Hebdo and on a Jewish supermarket.
One of the seriously wounded police officers sustained an injury to the carotid artery, and the other to the thorax, Heitz said.
The interior minister, Bruno Retailleau, was expected to travel to the scene of the attack later on Saturday.
Police established a security perimeter after the attack, which happened shortly before 4pm during a demonstration in support of Congo.
The suspect is Algerian and has been under judicial supervision and house arrest, and under an expulsion order from France, according to union sources.
“Horror has seized our city,” Mulhouse mayor Michèle Lutz said on Facebook. The incident was being investigated as a terror attack, she said, but “this must obviously still be confirmed by the judiciary”.
France’s national PNAT said it was taking charge of the investigation.
