A 13-year-old boy was thrown to the ground before his head was stamped on in an attack in Warminster.
A Wiltshire Police spokeswoman said the incident happened in the Imber Road and Fairfield Road area on 9 March. The victim was also slapped around the head and kicked.
Another teenage boy has since been arrested in connection with the assault, and released on police bail.
The spokeswoman appealed for any eyewitnesses to contact the force.
