Two more people have been arrested following the death of a 17-year-old boy.
Callum Riley was found with serious injuries in Heywood, Rochdale, on Saturday morning and died shortly afterwards.
On Sunday, a spokesman for Greater Manchester Police said a 25-year-old man had been arrested on suspicion of his murder.
A 23-year-old woman was arrested on suspicion of assisting an offender, the force said.
Two other men, aged 18 and 33, were arrested on suspicion of murder on Saturday and remain in police custody.
A 21-year-old woman who was arrested on suspicion of murder has been released and faces no further action.
Detective Chief Inspector Gina Brennand said: “Our thoughts remain with Callum’s family, who we are liaising with via a specially trained officer.
“Our investigation is very much ongoing and we are continuing to appeal for information.
“Officers from the Rochdale district will be providing a visible presence in the coming days to reassure members of the public – anyone with concerns can approach them.”
Anyone with information should contact police on 0161 8563400 quoting 723 17/09/22 or call Crimestoppers, anonymously, on 0800 555 111.