A 14-year-old boy has been arrested on suspicion of attempted murder after a man was stabbed on a bus, police said.
The 29-year-old man and 19-year-old woman were involved in an altercation as the bus travelled along Burton Road, Dudley on Friday.
West Midlands Police said the man was stabbed in the back and chest and the woman was punched in the face.
The man is in a stable condition in hospital, a spokesman said.
Det Sgt Phil Pullinger said: "Thankfully the man's stab wounds are not life-threatening and he remains in hospital in a stable condition where he is expected to make a full recovery."
The woman required stitches under her eye, he said.