Somerset police have arrested four people in connection with the death of a teenager in Taunton in the early hours of Sunday.
The victim has been named as 17-year-old Lloyd Fouracre who was local to the area.
He was with 10 friends in Gypsey Lane on the way home from an 18th birthday party when they were approached by four people and a fight broke out.
Lloyd was taken to Musgrove Park Hospital where he later died.
Detective Superintendent Arthur Lewis, who is leading the investigation, said: "It is essential that anyone who witnessed the incident or has any information about what has happened contacts us immediately."
Three 19-year-olds and an 18-year-old have been taken into custody are currently being questioned by officers.