Spencer Stone, hailed as a hero after a French train terror attack, has been stabbed in Sacramento, California.

He was attacked while defending a friend, and is currently in a stable condition at a local hospital, an Air Force official told the BBC.

Police say the stabbing took place on a Sacramento street corner in the early hours after an argument escalated.

Mr Stone, 25, is one of three Americans that helped to thwart a terror attack on a French train in August.

They were hailed as heroes for tackling a man who was carrying a Kalashnikov rifle, an automatic pistol with ammunition clips and a box cutter knife.

The men, assisted by other passengers, threw him to the floor of the carriage, removed his guns and restrained him.

Mr Stone was slashed by the attacker and later required surgery to reattach part of his hand.