One person has been killed and at least four others wounded in a gun attack in a Parisian suburb, which police have said they are treating as a terrorist incident.

French Prime Minister Sébastien Lecornu said the "very serious events" happened in Trappes, to the southwest of Paris, adding that the suspected attacker had been "apprehended and placed in police custody".

The National Anti-Terrorist Prosecutor's Office (PNAT) said it had taken on the investigation into the incident, which appeared to be "murder in connection with a terrorist enterprise".

Reports in French media suggest the number of injured may be higher and that a 12-year-old child may be among them.

The mayor of Trappes, Ali Rabeh, said that "an individual fired shots from his vehicle at several people he encountered" on Friday morning.

The alleged gunman "wandered aimlessly" through several neighbourhoods and "fired randomly" with the seeming intent of causing "as many casualties as possible", Rabeh told BFMTV.

"He wanted to cause…