Police are appealing for witnesses after a boy, aged 11, was reported to have been assaulted at a park in Worthing.
A spokesman said the boy was reportedly assaulted at Homefield Park, Worthing, at around 4pm on Tuesday, September 10.
Shortly afterwards, he returned to the park to retrieve his bike, to find the saddle had been damaged by fire, according to police.
A spokesman said: "Officers have engaged with the victim’s mother and enquiries are ongoing.
"Anyone who saw what happened is asked to report it online or call 101, quoting serial 40 of 11/09."
The incident comes less than two weeks after three boys were assaulted by members of a group of up to 15 youths in the same park.
The boys were 'verbally and physically assaulted' by three members of the group on Sunday, September 1, and criminal damage to their skateboards was caused by a can of spray paint, police said.
In a post on Facebook, a spokesman for The Friends of Homefield Park said they had noticed 'a rise in antisocial behaviour around the park in recent weeks' and urged people to continue to report all and any incidents to the police.