A gunman shot dead three people at a Kurdish cultural center and nearby Kurdish cafe in central Paris on Friday, prompting scores of protesters to take to nearby streets.
French Interior Minister Gerald Darmanin said the suspected assailant had clearly wanted to target foreigners, but there was no evidence yet that he had picked out Kurds specifically.
Darmanin also said the "exact motives of the killer" were yet unknown, but the suspect "obviously acted alone."
The suspect of French nationality was not on any radicalism watch lists, nor was he known for involvement in any of the recently dissolved extreme-right groups or other political movements, the minister said.
Multiple gunshots were fired on Rue d'Enghien at about midday, sowing panic on a street lined with small shops and cafes in the French capital's busy 10th district.
All three of the deceased victims were Kurdish, a lawyer for the Kurdish cultural center said.
As evening fell, riot police fired tear gas to push back an angry crowd a short distance from the scene of the shootings as projectiles were thrown at officers, rubbish bins and restaurant tables overturned and at least one car damaged.
Speaking to reporters at the shooting scene, Paris prosecutor Laure Beccuau confirmed that the suspect had two earlier criminal convictions.
The 69-year-old retired train driver was indicted for violence of racist nature with a weapon and premeditation for injuring two with a knife in a migrant camp in east Paris last year.
French President Emmanuel Macron described the shooting as a "heinous attack" in the heart of Paris.
Apart from the three killed, three others were injured, one of whom is in critical condition. An investigation was launched immediately after police arrested the suspect at the scene.
(With input from agencies)