An 18 year old who was attacked at a caravan park in Porthcawl last weekend has died in hospital.
Connor Marshall, from Barry, was found with serious injuries at Trecco Bay in the early hours of Sunday morning.
He was taken to the University Hospital of Wales where he died earlier.
South Wales Police have now started a murder investigation.
Detective Superintendent Paul Hurley said:
"Officers are continuing to conduct inquiries to establish the full circumstances of what happened. However, we would appeal to anyone who has any information that could assist us with our inquiries to contact us immediately.
"This was a brutal attack upon Connor with fatal consequences.
"I believe the person responsible may have shared information with friends, relatives or neighbours and I would urge anyone who has information or who may have been in the area of Trecco Bay between midnight and 7am on March 8 to contact the police.
"I would like to reassure residents and visitors to Porthcawl and Trecco Bay caravan park that this appears to be an isolated incident on a well-managed site. Parkdean Trecco Bay Management are continuing to work closely with South Wales Police.
"Our thoughts are with Connor's family and all those affected by this tragic incident.’'
Specialist forensic teams have been searching areas of the holiday park for evidence.
Parkdean, which runs Trecco Bay, said it was doing all it could to help the police with their inquiries.
A spokeswoman said:
"We are urging anyone with any information to please come forward.
"Our thoughts continue to be with the family (of the 18-year-old male) at this time.''
Anyone able to help police with their inquiries should contact 01656 655555, 101 or Crimestoppers on 0800 555111, quoting the reference number 1500080214.