PARIS — A knife-wielding assailant wounded two people in Paris on Friday near the site of the former Charlie Hebdo office — the scene of a 2015 terrorist attack targeting the satirical newspaper that is now the focus of a criminal trial.
A primary suspect was arrested a short time later. Gérald Darmanin, the French interior minister, said Friday evening that the suspect, believed to be an 18-year-old Pakistani, had not been previously identified by the authorities as a possible extremist.
But he called the attack an “act of Islamist terrorism” because of its location — in front of the building where Charlie Hebdo had its offices at the time of the January 2015 attack that left 12 dead — and because of the nature of the assault, against random bystanders. French prosecutors have opened a terrorism investigation.
“It is a new, bloody attack against our country,” Mr. Darmanin told France 2 television.
Prime Minister Jean Castex, who cut short a scheduled speech after the attack occurred, told reporters that it happened “in a symbolic location,” not far from a mural that pays tribute to the victims of the 2015 massacre. Authorities also pointed to the timing of the attack, which came amid the ongoing trial of several people accused of aiding the 2015 assailants.
The authorities did not provide evidence of a link to the past attack, however, or say if the suspect had any affiliation with a terrorist group.
The victims’ lives were not in danger, Mr. Castex said. They were employees of Premières Lignes, a documentary production company next door to the former Charlie Hebdo office. Some of its employees were the first witnesses to the January 2015 attack.
Luc Hermann, a journalist and filmmaker at Premières Lignes, told the BFM TV news channel that the two employees, a man and a woman, appeared to have been set upon “totally by chance.”
Mr. Hermann said that it was “a surprise attack, by a man armed with a very large bladed weapon,” who inflicted “extremely violent blows.”
But Mr. Hermann blamed the authorities for failing to secure the area surrounding Charlie Hebdo’s former offices, noting that there had been “absolutely no security” on the street since the start of the trial.
Mr. Darmanin, the interior minister, said he had asked Paris police to review why the threat in that neighborhood had been “underestimated.”
Al Qaeda had recently issued new threats against Charlie Hebdo, which moved after the 2015 attack to highly secure offices elsewhere. The threats followed the newspaper’s decision to reprint satirical cartoons of the Prophet Muhammad at the opening of the trial.
A few hours after the attack on Friday, the weekly wrote on Twitter that its “entire team offers its support and solidarity to its former neighbors and colleagues” at Premières Lignes, “and to the people affected by this heinous attack.”
The main suspect was arrested in the Bastille neighborhood, not far from the site of the attack, the police said.
Jean-François Ricard, France’s top antiterrorism prosecutor, told reporters that the police had taken a second person into custody to verify “their connections to the main perpetrator.”
The assailant attacked “two people he knew nothing about and who were just taking a cigarette break,” Mr. Ricard said.
Five other people were taken into custody later on Friday, although no details were disclosed. The French police routinely carry out sweeping arrests of acquaintances of the main suspects in terrorist attacks, sometimes releasing them shortly afterward without charge.
Mr. Darmanin, the interior minister, said the police were still trying to determine the primary suspect’s exact identity and age. Preliminary investigation, he said, had determined that the suspect had arrived in France three years ago as an “isolated minor,” and had been briefly under arrest a month ago for carrying a weapon — a screwdriver. The exact circumstances of that arrest were unclear.
Minutes after the attack, dozens of politicians from across the political spectrum posted messages on Twitter in support of the victims, some with the hashtag #JeSuisCharlie or #IAmCharlie, a popular refrain in the wake of the 2015 attack.
Marika Bret, Charlie Hebdo’s head of human resources, said this week that she had been forced to leave her home 12 days ago after her security guards received detailed and precise threats against her.
Speaking to the weekly Le Point, Ms. Bret, who has been living under police protection since 2015, said that the threats reflected “the unprecedented level of tension we are facing.”
Jean-Charles Brisard, director of the Paris-based Center for the Analysis of Terrorism, wrote in an op-ed in Le Figaro on Thursday — a day before the knife assault — that the trial for the January 2015 attacks had led to “renewed activity and hostility” in Islamist circles, and heightened threats.
Mr. Brisard, writing along with Thibault de Montbrial, a lawyer representing a former Charlie Hebdo journalist at the trial, added that the release of numerous convicts in terrorism cases whose sentences will soon end, combined with other coming terrorism trials, “lead us to fear a resurgence of terrorist attacks.”
Mr. Darmanin, the interior minister, said that more than 100 people convicted on a range of terrorism charges were expected to be released from prison in 2020 and 2021.
“We are still at war with Islamist terrorists,” he said, adding that 32 attacks had been thwarted in the past three years and that the threat had been “mutating” from organized to isolated acts.
In the 2015 attack, the brothers Chérif and Saïd Kouachi stormed into the building that housed the satirical newspaper and fatally shot a maintenance worker. The brothers then forced at gunpoint a cartoonist who had just stepped outside to enter a security code to access the offices.
The gunmen entered as journalists were holding a weekly news meeting and opened fire with semiautomatic rifles, killing 10 people and critically injuring four others. They left the building less than two minutes later and shot and killed a police officer who tried to stop them as they fled. After a two-day manhunt, the Kouachi brothers were killed in a shootout with the police in a small town north of Paris.
Al Qaeda’s branch in Yemen later claimed responsibility for directing the attack.
“Since the start of the trial and with the republication of the cartoons, we have received all kinds of horrors, including threats from Al Qaeda and calls to finish the work of the Kouachi brothers,” Ms. Bret said.
Elian Peltier contributed reporting from London.