A murder inquiry has been launched after an 18-year-old man died following what is thought to be a fall-out among friends.
The victim, from Birmingham, died in hospital on Friday night after being assaulted on Thursday afternoon, West Midlands Police said.
He had returned home after the incident in High Street, Quinton, in Birmingham, but was then taken to hospital where he remained in a critical condition until the decision was taken to turn off his life support machine.
Three youths, two aged 16 and one aged 17, have been arrested in connection with the incident and remain in police custody where they are being questioned, a police spokesman said.
Detective Chief Inspector Clare Cowley said officers were conducting local inquiries and making house-to-house visits to establish the circumstances surrounding the assault.
Appealing for information from the public, she said: "High Street is just off the busy Hagley Road West and Quinton Expressway and so many people would have been in the area passing by at the time.
"We still need to find out exactly what went on that led to the victim sustaining his injuries."
