A suspect arrested Wednesday has admitted to the weekend stabbing of a French soldier in Paris and was probably acting based on his "religious ideology", Paris prosecutor François Molins said.
Molins said the man, named Alexandre and who turns 22 on Thursday, had converted to Islam and was known to police after undergoing an identity check in 2007 for praying on the street.
The prosecutor said the man "admitted to the act" during his arrest early Wednesday in the Yvelines region just west of Paris, following the attack on Saturday in which Private First Class Cedric Cordiez was stabbed in the neck.
Molins added that the suspect had "a fairly clear intent to kill" during the attack, which took place in a busy underground shopping and transport hub while Cordiez was on patrol with two colleagues.
The stabbing echoed the brutal killing of another soldier in London last week and authorities are seeking to determine if the Paris incident was a copycat attack.
The head of investigative police, Christian Flaesch, said there had been no previous indications of the suspect's involvement in violent extremism.
"Other than the praying in the street, there were no other elements that could have indicated he was dangerous," Flaesch said, adding that the man was from a "family that seems completely honourable".
Molins said the suspect had shown an "impressive determination" to carry out the attack, stabbing the soldier "several times" with a fold-out knife.
He said video footage showed the suspect buying two knives an hour prior to the attack and praying eight minutes before the stabbing.
Molins added the suspect was known to police for various misdemeanors but did not have a criminal record.
He was arrested at the home of a friend, who Molins said was not connected with the crime and did not know that the suspect was being sought.
Police said he the suspect was identified thanks to video footage from the crime and traces of his DNA found on items left at the scene in a plastic bag, including a knife and a bottle.
In his statement Interior Minister Manuel Valls said investigators were seeking to know more about the suspect's "motivation, background and family environment".
On French television, Valls warned of a growing number of young radicals in France similar to Mohamed Merah, the Islamist gunman who killed seven people in and around the southwestern city of Toulouse last year.
Valls said there are "several dozen, perhaps several hundred, potential Merahs in our country," saying young French Muslims were being "radicalized" on the Internet and by extremist imams.
The attacker, described by police at the time as bearded and around 1.9 metres (six feet three inches) tall, approached 23-year-old Cordiez while he was on patrol with two colleagues, stabbed him in the neck and then disappeared into a crowd.
Sources close to the investigation have said that the suspect was seen on video praying a few minutes prior to the attack.
Cordiez was released from a military hospital on Monday and rejoined his unit.
The key suspect in the London attack, Michael Adebolajo, was captured on video carrying bloodied knives and a meat cleaver after the attack, saying he had murdered off-duty soldier Lee Rigby because British troops were killing Muslims.