A baby is in hospital with a serious injury after being struck in the eye with a golf ball.
The three-month-old boy was hit at a playground in Sheldon, Birmingham at 20:40 BST on Friday.
A 36-year-old man was arrested on suspicion of assault and is also in hospital, West Midlands Police said.
Officers were called to the scene, in a park outside Radley Court on Sheldon Heath Road, by ambulance crews.
The force urged anyone with information to contact them.