Four people have been hurt, two of them seriously, in a knife attack in Paris near the former offices of the satirical magazine Charlie Hebdo, officials say.
A suspect has been detained in the nearby Bastille area after police said at least one person had fled the area by metro.
A security cordon has been set up around the offices in the 11th arrondissement.
The public were told to avoid the area.
Several schools in the area have also been locked down, local media say.
A blade – described as a machete or a meat cleaver – was recovered at the scene of the attack.
The arrested suspect was detained with blood on his clothing, French media reports say.
The attack comes as a high-profile trial is under way in Paris of 14 people accused of helping two jihadists carry out the 2015 attack on Charlie Hebdo, in which 12 people were killed.