A woman has been decapitated in a suspected terror attack in Nice, French police say.
Three people have died and several others are injured after a knife attack reportedly took place near the Notre Dame church.
Nice’s mayor Christian Estrosi tweeted: “Everything suggests a terrorist attack,” and the attacker shouted “Allahu Akbar”.
He told reporters: “The suspected knife attacker was shot by police while being detained, he is on his way to hospital, he is alive.”
President Macron rushed to a crisis centre overseeing the aftermath of the attack.
French interior minister Gerald Darmanin said a police operation is under way and encouraged people to stay away from the area. He is holding a crisis meeting into the incident.
French politician Marine Le Pen also spoke of a decapitation having occurred in the attack.
Meanwhile, the French anti-terrorist prosecutor’s department has been asked to investigate the incident.
The assailant was believed to be acting alone, an official said.
French parliament suspended a debate on new virus restrictions and held a moment of silence for the victims.
Reuters journalists at the scene said police armed with automatic weapons had put up a security cordon around the
Notre Dame church, which is on Nice’s Jean Medecin avenue, the city’s main shopping thoroughfare.
Sounds of explosions could be heard as sappers exploded suspicious objects.
It comes as the country is under high alert for terrorist attacks following the beheading earlier this month of French middle school teacher Samuel Paty in Paris.
The attacker had said he wanted to punish Mr Paty for showing pupils cartoons of the Prophet Mohammad in a civics lesson.
It was not immediately clear what the motive was for the Nice attack, or if there was any connection to the cartoons, which Muslims consider to be blasphemous.
Mr Estrosi said said the victims had been killed in a “horrible way”.
“The methods match, without doubt, those used against the brave teacher in Conflans Sainte Honorine, Samuel Paty.”
Since Mr Paty’s killing, French officials – backed by many ordinary citizens – have re-asserted the right to display the cartoons, and the images have been widely displayed at marches in solidarity with the killed teacher.
That has prompted an outpouring of anger in parts of the Muslim world, with some governments accusing
Emmanuel Macron of pursuing an anti-Islam agenda.
Two people were stabbed and wounded in Paris on 25 September this year near the former offices of the Charlie Hebdo satirical magazine, where Islamist militants carried out a deadly attack in 2015 killing 12.
A man originally from Pakistan was arrested over the attack.