Four people, including a 12-year-old boy, were being questioned on Sunday night by detectives investigating a weekend murder in east Belfast.
A man aged 21 and a woman aged 24 were detained on Saturday in connection with the murder of Matthew Goddard, 41, on Christmas Eve.
A 17-year-old male youth and a 12-year-old boy were arrested on Sunday following searches in the area.
Mr Goddard, who was known as ‘Mat’, was found in his Chobham Street home around 9.40pm on Christmas Eve by a friend who called to collect Christmas presents. He was last seen alive around 6pm on December 23.
Police said he was killed in a “sustained and brutal attack” and had been beaten with his electric guitar and other objects.
They said they were “not prepared to disclose the exact cause of death at this stage”.
The murder victim leaves behind his mother, father and a half brother.
Speaking at a press conference on Saturday, Senior Investigating Officer DCI John McVea said: “Mr Goddard suffered a brutal and violent attack in the living room of his home – a place where he should have felt safe. Mr Goddard was not previously known to police.
“We believe he may have been involved in drugs and this is one of a number of lines of enquiry police are investigating.
“At this stage we do not know the reason why Mr Goddard was attacked, but this type of vicious behaviour has no place in society.
“One of Mr Goddard’s hobbies was playing guitar and we believe his electric guitar was used at some stage during the attack however we are not prepared to disclose the exact cause of death at this stage. We are appealing for people to come forward with information to help bring those responsible for this ruthless murder before the courts”.
He appealed for anyone in the Chobham Street area between teatime on December 23 and 9.40pm on December 24, and noticed anything suspicious, to contact detectives.
Alliance councillor Maire Hendron has expressed her shock at Mr Goddard’s murder.
“This was a brutal and callous murder which must be condemned by all,” she said.