Bus drivers in southwest France are refusing to work after a Sunday night attack left one of their colleagues brain dead. A police source says the driver, a man in his 50s, was attacked by a group of passengers in Bayonne and suffered severe head injuries after he reportedly refused to let them board without tickets and face masks, the BBC reports. Masks are required on all public transportation in the country. Five suspects were arrested Monday, the Local reports. Bus drivers protesting the attack say regional transport network company Chronoplus has not taken adequate measures to ensure their safety. (More France stories.)