(CNN) -- At least six people were killed and 22 injured in a train derailment on Friday just south of Paris, French President Francois Hollande said.
The announcement by Hollande revised the death toll down from seven dead in Bretigny-sur-Orge.
Hollande arrived at the scene while rescue operations were under way.
It was still unknown what caused the derailment of the regional train that left the Paris Austerlitz station Friday afternoon, said Guillaume Pepy, president of SNCF, the French national railway company.
SNCF characterized it as an accident.
Carrying about 370 people, the train was passing through the Bretigny-sur-Orge station. It did not have a scheduled stop there, Pepy said.
It was bound for the city of Limoges, Valls said.
The last four cars went off the track, the railway company said. One was lying on the track, it said.
A photo airing on BFMTV showed part of the train lying on the station's platform.
Hollande, who said he's traveled on the route before, announced three investigations -- a judiciary inquiry, an internal inquiry within SNCF and an inquiry that will be handled by the country's transport ministry.
Firefighters were on the scene as rescue operations continued into the evening, Pepy added.
Experts began their investigation at the scene.
"The first thought we all have is one of solidarity toward the victims and their families, and we feel a strong emotion because rail accidents are upsetting to the whole public," Pepy said, becoming emotional as he spoke.
Earlier Friday, French police said that at least eight people had been killed, according to CNN affiliate BFMTV.
CNN's Pierre Meilhan contributed to this report.