There are reports of a shooting in southern France after three armed men allegedly jumped off a train from Paris and opened fire.

Nimes railway station has been evacuated and one person has reportedly been arrested, Sky News reports.

The Mirror are reporting that police are searching a train for suspects and that passengers are being told to put their hands up.

The men boarded the train at Nimes, just east of Spain.

Local police are urging people to avoid the area, saying a possible attack is ongoing.

Sky News is reporting one arrest, but there is no word on casualties.

It is the first day of the Vuelta a Espana cycling tournament.