Officers said a man was seriously injured in Watson Close, Maidenbower, just after 6.30pm last night (November 15).
Emergency services attended the incident but the 24-year-old was pronounced dead at the scene.
Police said they had launched a murder investigation following his death. Two people were arrested that evening whilst a third was arrested in the early hours of this morning (November 16).
Investigations have continued throughout today and police said four more people had been arrested in connection with the incident.
Officers said three 17-year-old boys were arrested after a car was pulled over at Three Bridges railway station shortly after 11.30am today. The trio were arrested suspicion of assisting an offender.
A 24-year-old man from Horley was also arrested shortly before 11am on suspicion of assisting an offender.
Detective Chief Inspector Andy Richardson said: “We have now arrested seven people in connection with this investigation and we believe that they and the victim are all known to each other.
“However, we are still seeking one more person who we would like to talk to about the events in Watson Close, Maidenbower on Thursday evening. Anyone who witnessed the incident, the events leading up to it or who has any information to assist our enquiry who has not yet talked to police is asked to report online or call 101 quoting Operation Horseman.”
Police said all seven people arrested remained in custody at 1pm on Friday (November 16).