Demonstrators on the Place de la Republique held aloft posters declaring: "No to totalitarianism of thought" and "I am a teacher" in memory of the decapitated victim Samuel Paty
Thousands of people rallied in central Paris on Sunday in a defiant show of solidarity with a teacher beheaded for showing pupils cartoons of the Prophet Mohammed.
Demonstrators on the Place de la Republique held aloft posters declaring: "No to totalitarianism of thought" and "I am a teacher" in memory of the decapitated victim Samuel Paty.
Some chanted "I am Samuel", echoing the "I am Charlie" cry that travelled around the world after Islamist gunmen killed 12 people at the Charlie Hebdo satirical magazine in 2015 for publishing caricatures of the Islamic prophet.
Between bursts of applause, others recited: "Freedom of expression, freedom to teach."
Demonstrations are also planned for the cities of Lyon, Toulouse, Strasbourg, Nantes, Marseille, Lille and Bordeaux.
Paty's assassination has shocked the country and brought back memories of a wave of Islamist violence in 2015 that started with the Charlie Hebdo massacre.
Those killings saw some 1.5 million people gather on the Place de la Republique in support of freedom of expression.
Ahead of on Sunday's gathering, Education Minister Jean-Michel Blanquer called on "everyone to support the teachers," telling broadcaster France 2 that it was vital to show "our solidarity and unity."
Prime Minister Jean Castex and Paris mayor Anne Hidalgo were among those present.
The aggrieved father had named Paty and gave the school's address in a social media post just days before the beheading which President Emmanuel Macron has labelled an Islamist terror attack.
Suspect increasingly religious
Ricard did not say if the attacker had any links to the school, pupils or parents, or had acted independently in response to the online campaign.
The prosecutor said the attacker had been armed with a knife, an airgun and five canisters. He had fired at police and tried to stab them as they closed in on him.
He was in turn shot nine times.
The Russian embassy in Paris said the suspect's family had arrived in France from Chechnya when he was six and requested asylum.
Locals in the Normandy town of Evreux where the attacker lived described him as low key, saying he got into fights as a child but calmed down as he became increasingly religious in recent years.
Friday's attack was the second of its kind since a trial started last month over the January 2015 Charlie Hebdo massacre.
The magazine republished the cartoons in the run-up to the trial, and last month a young Pakistani man wounded two people with a meat cleaver outside the magazine's former office.
Ricard said Paty's murder illustrated "the very high-level terrorist threat" France still faces but added the attacker was not known to French intelligence services.