The police said a suspect was arrested shortly after the attack, which came as a trial is underway over the January 2015 attacks that targeted the satirical newspaper.
“An attack with a bladed weapon was carried out in the 11th arrondissement in front of the former offices of Charlie Hebdo,” Jean Castex, the prime minister, said as he cut short a scheduled speech.
A suspect was arrested a short time later in the Bastille neighborhood, an area in Paris not far from the site of the attack, according to the police. The person was not immediately identified and it was unclear how he or she was linked to the attack. The office of France’s antiterrorism prosecutor said on Friday that it had opened an investigation.
The authorities initially gave a higher number for people injured, revising it later on Friday.
Emmanuel Grégoire, the deputy mayor of Paris, in a post on Twitter urged people to avoid the Richard-Lenoir neighborhood — where Charlie Hebdo had its offices before the terrorist attack in January 2015 that left 12 people dead.