Two people were seriously injured in a knife attack in Paris near the former offices of the satirical magazine Charlie Hebdo, officials said.
The suspect was detained in the nearby area of the Bastille. A second suspect has also been arrested, reports said.
The anti-terrorist police have taken over the investigation.
A security cordon has been set up in the 11th district of East Paris. The public was told to avoid the area.
A blade – described as a machete or a meat cleaver – was found at the site of the attack near Boulevard Richard Lenoir.
The arrested suspect was detained with blood on his clothes, French media reported.
Initial reports said four people were injured.
The attack comes as a high-ranking trial is under way in Paris against 14 people accused of helping two jihadists carry out the 2015 attack on Charlie Hebdo, in which 12 people were killed.
The two wounded are employees of a television production company, one of their colleagues told Agence France-Presse.
“Two colleagues were smoking a cigarette in front of the building, on the street. I heard shouts. I went to the window and saw one of my colleagues, covered in blood, chased by a man with a machete on the street,” another staff member at the production company Premières Lignes.
The company has offices in Rue Nicolas Appert, a side street next to Boulevard Richard Lenoir, where Charlie Hebdo’s former offices are located.
The satirical magazine has since moved to a secret location.