The primary suspect in Friday's knife attack outside the former Paris offices of satirical newspaper Charlie Hebdo has confessed to the stabbings, sources said on Saturday.
The man, who said he was born in Pakistan and is 18, "takes responsibility for his action which he places in the context of the republication of cartoons" of the Prophet Mohammed in Charlie Hebdo, one of the sources said.
Two people were wounded in the attack outside Charlie Hebdo's former offices, in Paris's eastern 11th arrondissement (district). The suspect, his face speckled with blood, was arrested by police on the steps of the Bastille Opera House, not far from the scene.
Witnesses described seeing the assailant striking the victims with a large meat cleaver, which was later found near the site of the attack.
France's PNAT specialist anti-terror prosecution office said it has opened a probe into charges of "attempted murder related to a terrorist enterprise" as well as "conspiracy with terrorists".
Seven people including the main suspect were being held for questioning in connection with the attack, which Darmanin said was "clearly an act of Islamist terrorism".
"This is a new bloody attack on our country," Interior Minister Gerald Darmanin told France 2 television.
Prime Minister Jean Castex, visiting the scene, said the lives of the two victims "are not in danger, thank God".
The Premieres Lignes news production agency said the wounded were its employees - a man and a woman taking a cigarette break outside.
"They were both very badly wounded," the founder and co-head of Premieres Lignes, Paul Moreira, told AFP.
Another employee, who asked not to be named, said he heard screams.
"I went to the window and saw a colleague, bloodied, being chased by a man with a machete."
The company specialises in investigative reports and produces the prize-winning Cash Investigation programme.
In a Twitter post, Charlie Hebdo expressed its support for "the people affected by this odious attack".
They were victims of "fanaticism" and "intolerance", Charlie Hebdo said, calling the main suspect and his possible accomplice "terrorists".
'Underestimated the threat'
The stabbing came three weeks into the trial of suspected accomplices in the 2015 massacre of Charlie Hebdo's staff, which was claimed by a branch of al Qaeda.
The newspaper has angered many Muslims around the world by publishing cartoons of the Prophet Mohammed over the years, and in a defiant gesture reprinted some of the caricatures ahead of the trial.
Twelve people, including some of France's most celebrated cartoonists, were killed in the attack on Charlie Hebdo by brothers Said and Cherif Kouachi, on January 7, 2015.
A female police officer was killed a day later, followed the next day by the killing of four men in a hostage-taking at a Jewish supermarket by gunman Amedy Coulibaly.
The trial has reopened one of the most painful chapters in France's modern history, with harrowing testimony from survivors and relatives of those who died.
The magazine received fresh threats from al Qaeda this month after it republished the controversial cartoons.
More than 100 French news outlets on Wednesday called for continuing support for Charlie Hebdo against what they described as the "enemies of freedom".
Just this week, police relocated the paper's head of human resources, Marika Bret, from her home following death threats.
Darmanin said he had asked the Paris police chief "why we underestimated the threat" in the street next to Charlie Hebdo's former offices.
The co-head of Premieres Lignes, Luc Hermann, told BFMTV that since the start of the trial "there has been absolutely no security for this street and symbolic building".
(FRANCE 24 with AFP, AP)