French police have arrested an 84-year-old man suspected of firing shots outside a mosque in the south-western city of Bayonne.

Police said a man was trying to set fire to the mosque's door at around 3.20pm local time when he shot two men aged 78 and 74, who had surprised him. Both victims were treated in hospital for serious injuries. 

After throwing an incendiary device into the mosque, the assailant also tried to set fire to a car as he fled the scene. 

A suspect was arrested soon after, near his home close to Bayonne. A police source told Reuters that the suspect is believed to have been a far-right Front National candidate in the 2015 local elections, but has no police record. 

Patrice Peyruqueou, a police union official in Bayonne, said: "The suspect threw an incendiary device at the mosque and then fled in his car. He was arrested outside his home."