A bus driver in France has been declared brain dead after being attacked by several people he refused to let aboard because they were not wearing face masks as required during the coronavirus outbreak.

A police source in Bayonne, near the ritzy Atlantic resort of Biarritz in southwestern France, said one person was in custody and other suspects were being sought.

When the driver, in his 50s, tried to prevent the individuals' entry on Sunday night, he was repeatedly punched in an assault that resulted in serious head injury.