A stranger walked a seven-year-old girl to a park and then hit her in the face, police said.
The man, aged between 18 and 25, approached the girl in the Minories Road area of Tidworth, Wiltshire, at 14:45 BST on Friday.
He then walked with her to a nearby park where he hit her in the face, officers said. The girl managed to escape and run home uninjured.
Wiltshire Police said “it appears the man was not known to the girl”.
Det Sgt Nick Bailey said officers had searched the area and made house-to-house inquiries.
“This incident is understandably distressing for this little girl and we are keen to speak to anyone who has any information,” he added.
The attacker is described as about 6ft (183cm) tall and of a thin build. He was wearing a black hat, black trousers and a black t-shirt.