A gunman killed one person and wounded several others, including a 12-year-old girl, in a suspected Islamophobic attack west of Paris on Friday, October 23, prompting a terrorism investigation.
French authorities arrested a 39-year-old suspect following shootings across Trappes and nearby La Verriere in the Yvelines district.
Officials reported conflicting casualty figures, with four or five people wounded.
Interior Minister Laurent Nunez said the suspect fired an automatic weapon from a vehicle at a petrol station, medical centre and children's playground during an attack lasting less than 15 minutes.
Three victims, including the girl, reportedly sustained life-threatening injuries.
French broadcaster BFM reported that the child had been struck eight times.
Trappes Mayor Ali Rabeh described the shooting as apparently indiscriminate and potentially motivated by anti-Muslim hatred.
He said two victims were of African and North African origin.
France's national antiterrorism prosecutor's office, PNAT, assumed responsibility for the investigation, examining whether racial or religious hatred motivated the attack.
President Emmanuel Macron expressed solidarity with the victims, their families and residents of Yvelines.
The unidentified suspect reportedly lived in Plaisir, another municipality in Yvelines.
Authorities have not established a definitive motive.
The shooting occurred amid heightened tensions following violent demonstrations across France on October 17, when protesters clashed with police, vandalised businesses, looted shops and attacked public buildings.
Authorities are preparing for further demonstrations on Saturday against rising living costs, involving students, trade union members and activists associated with the yellow vest movement.
Nunez announced the deployment of 70,000 officers nationwide, supported by helicopters, armoured vehicles, water cannon and specialised police units protecting public buildings.
Several planned demonstrations have been prohibited following last weekend's unrest.
Political divisions have intensified, with some far-right politicians criticising the government's response to disorder and left-wing groups questioning restrictions on demonstrations.
Rabeh also urged condemnation of inflammatory rhetoric following the shooting.
Investigators continue examining the suspect's intentions as France confronts both the aftermath of the deadly attack and renewed concerns over public security.