A young man has been found beaten and naked in a taped-up wheelie bin in County Antrim.
He suffered cuts and bruising and is stable in hospital following the attack near Sentry Hill in Ballymena, police said.
The victim was discovered by a man walking his dog.
SDLP councillor Declan O'Loan said he was found yesterday in a council-owned park near an old-fashioned sports hall.
"While the full facts are not clear this was obviously a very serious incident and the young person concerned was treated in a disgraceful and degrading fashion," he said.
"There would have been a number of people involved in such an incident and it is likely quite a number of people have useful information in relation to what happened and I would encourage them to go to the police."
Police arrested three men and a woman.
PSNI d etective chief inspector Tracey Mageean said: "A man has sustained injuries which are not believed to be life threatening and is now in a stable condition in hospital."
She confirmed he was inside a wheelie bin which had been taped up and was found by a person out walking a dog. The dog walker called the ambulance service and police immediately.
"Detectives have launched a full investigation with a definite line of inquiry, as evidenced by our four arrests," the senior officer added.
"At this time, I do not believe that there is a sectarian motive nor do I consider that it is paramilitary related. This incident has shocked local people as this is an area where crime isn't prevalent."
The four people arrested will be interviewed, and police said the investigation was at a very early stage but appealed for anybody with information to contact them.