A 16-year-old boy arrested on suspicion of causing death by dangerous driving after a collision on the Shirenewton caravan site, east of Cardiff, has been released on bail pending further enquiries.
A seven-year-old boy was taken to the University Hospital of Wales in Cardiff, where he died from his injuries. Specially-trained police officers are supporting the family.
Police are still investigating the incident, which happened at around 3pm on Saturday. They are appealing for any witnesses to come forward.
More top news
A full-time carer from Port Talbot is celebrating after winning £1m on the EuroMillions.
Kane Wannell jailed for holding up a Post Office with a fake gun and pointing it at the owner and customer.
Outbreaks of mostly light rain will arrive from the north tonight with hill fog likely.