Brahim Aouissaoui, of Tunisian origin, illegally crossed the border to France just days before the stabbing stabbing that killed three people outside a church in Nice.

French prosecutors on October 29 said Aouissaoui, 21, left his home town of Tunisia for the island of Lampedusa, Italy, on September 20 and was on a quarantine boat for 14 days before being transferred to the inland city of Bari.

Aouissaoui then received a "exit note", asking to leave Italy within seven days.

French officials said Aouissaoui did not have any identification on his body when arrested by police after the stabbing, but brought a document stating his name issued by the Italian Red Cross.

On the morning of October 29, Aouissaoui attacked many people outside a church in Nice city in the south of France, killing three people, of which at least one was cut off, and many were injured.

The stabbing comes almost two weeks after French teacher Samuel Paty was beheaded on October 16 outside Bois d'Aulne High School, after showing students a caricature of the prophet Mohammed.

France has been on high alert for terrorist attacks since the January 2015 attack on satirical magazine Charlie Hebdo, which killed 12 people.

A wave of protests against France and President Emmanuel Macron recently spread after he angered many Muslim nations for supporting publishing of the cartoonist Mohammed, a taboo against Islam.