In the village of Saint-Martin-Vésubie in the French Alps, where Hervé Gourdel lived and worked, there was shock and disbelief at news that he has been beheaded by extremists.
Across France, flags were at half-mast and will continue to be throughout the weekend.
President Hollande said Gourdel was killed for no other reason than that he was French. His countrymen and women are united in their condemnation of his death and sympathy for his family.
One French woman said: “Today the mountains are in grief. France is in grief, humanity is in grief. So it was important for us to be here today.”
In Algeria, there was horror at the gruesome killing that had taken place in their country.
One man said: “Islam has nothing to do with these kind of deeds. Islam is a religion of peace; I am so sorry this happened.”
Algerians held rallies to denounce the beheading and called for their government to deal with the instability and extremism in the Kabylie region where the killing happened.