A man armed with a meat cleaver wounded two in Paris Friday outside the former offices of satirical weekly Charlie Hebdo before being arrested by police, three weeks into the trial of suspected accomplices in the 2015 massacre of the newspaper's staff.
France's PNAT specialist anti-terror prosecution office said it had opened a probe into charges of "attempted murder related to a terrorist enterprise" as well as "conspiracy with terrorists."
Charlie Hebdo has angered many Muslims around the world by publishing cartoons of the Prophet Mohammed over the years, and in a defiant gesture ahead of the trial reprinted some of the caricatures on its front cover this month.
Twelve people, including some of France's most celebrated cartoonists, were killed in the January 7, 2015, attack on Charlie Hebdo by Islamist gunmen.
Paris police said two people were "critically wounded" in Friday's attack near the paper's former offices in the capital's 11th district. The magazine's new address is kept secret for security reasons.
A large meat cleaver found near the scene is believed to have been used by the attacker.
Prime Minister Jean Castex, visiting the scene with Paris Mayor Anne Hidalgo, 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.
Paris prosecutors said the "main perpetrator" was arrested near the Place de la Bastille square, not far from the scene of the crime.
According to PNAT head Jean-Francois Ricard, the suspect was an 18-year-old man. Initial indications are that he was born in Pakistan.
A second person, aged 33, was arrested in the Bastille area later and held for questioning to determine possible links to the "main perpetrator," said Ricard. The reason for the second arrest has not been divulged.
Five schools in the area went into lockdown for several hours after the attack, and half a dozen nearby metro stations were closed.
"Around noon we went for a lunch break at the restaurant. As we arrived, the manager started shouting 'Go, go there is an attack...' We ran to lock ourselves in our shop with four customers," Hassani Erwan, a 23-year-old barber, told AFP.
Castex reiterated the government's "firm commitment to combat terrorism by all possible means."
In a Twitter post, Charlie Hebdo expressed its "support and solidarity with its former neighbours... and the people affected by this odious attack."
The stabbing came amid the trial of 14 alleged accomplices of brothers Said and Cherif Kouachi, the perpetrators of the January 2015 attack on Charlie Hebdo that was claimed by a branch of Al-Qaeda.
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 defendants stand accused of having aided and abetted the perpetrators of the three-day crime spree, themselves killed by police.
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 controversial cartoons of the Prophet Mohammed ahead of the court case.
The massacre at the newspaper sparked international outrage and heralded a wave of Islamist violence that has left 258 people dead and raised unsettling questions about France's ability to preserve security and harmony in a multicultural society.
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 last week, police relocated the paper's head of human resources, Marika Bret, from her home following death threats.
The trial, which opened on September 2, was postponed Thursday after accused Nezar Mickael Pastor Alwatik fell ill in the stand.
But it resumed Friday morning, with the suspect back in the box, after a coronavirus test came back negative.