Police are investigating a playground assault on a four-year-old boy who was pushed, punched and swung around by his hands and feet.
The boy was in a play area with his eight-year-old sister and his 11-year-old brother nearby when he was confronted by four boys aged around 11 and 12.
Two of the boys pushed him to the ground, punched him and then swung him by his hands and feet before letting go, causing him to collide with a climbing frame.
Police described it as a "vicious and disturbing assault" on an innocent boy with an undisclosed medical condition who has been left distressed.
He sustained a swollen forehead in the assault in the grounds of Shinewater Community Centre in Eastbourne, East Sussex, at around 2.30pm on September 25.
A man who saw what was happening shouted at the boys but was unable to enter the play area because the boys had pushed their scooters and bicycles against a gate.
The man, who has not been identified, spoke to the little boy and his sister before alerting their mother, a Sussex Police spokesman said.
Pc James Mackintosh, of Sussex Police, said: "This was a vicious and disturbing assault on an innocent young boy, which has been very distressing for the victim and his family.
"The boy has an existing medical condition, which could have resulted in far more serious injuries."
He added that a full investigation was under way as he appealed for witnesses.
The four boys were seen walking off in the direction of a Co-op store in Milfoil Drive. Two suspects are due to be spoken to in connection with the inquiry.