A gunman opened fire on a packed Greyhound bus in California, killing one passenger and wounding five others before the driver pulled over and managed to force the killer off, authorities said.
The suspect was taken into custody without incident and the motive was not immediately known, California Highway Patrol Sergeant Brian Pennings said.
The dead passenger on the bus, which was travelling from Los Angeles to San Francisco, was identified as a 51-year-old woman from Colombia.
Two victims were taken to hospital with serious injuries, Mr Pennings said.
The shooting took place shortly before 1.30am local time in the small community of Lebec, about 70 miles north west of Los Angeles, as the bus was travelling along a mountainous stretch of Interstate 5 with 43 people aboard, authorities said.
"The driver of the bus immediately pulled to the right shoulder and somehow - we're still trying to figure out how this happened - were able to coerce the suspect off of the bus," Mr Pennings said.
After leaving the gunman behind, the driver continued on to the next exit and pulled into a petrol station.
"His actions were very appropriate and one could say heroic," Mr Pennings said.
Highway patrol officers found the suspect a few minutes later.
A handgun believed to have been used in the shooting had been left on the bus, Mr Pennings said.
The shooting happened when the bus was at the top of Tejon Pass, which rises to an elevation of more than 4,100ft in Lebec.
Greyhound prohibits passengers from bringing guns, explosives or dangerous chemicals on board its buses or in their luggage, according to its website.