Emergency services attended an address in Brimstone Road on Saturday evening (October 31).
A Sussex Police spokesperson said: “It followed a report of an altercation in Hayley Road, Lancing, at 6.45pm.
“A 21-year-old man sustained an injury to his hand, consistent with a stabbing, and attended hospital for treatment.”
The police force said a teenager was traced in connection with the incident and arrested ‘on suspicion of causing grievous bodily harm’.
In an update issued on Monday (November 2), the police force said the boy had been bailed, pending further enquiries, and the investigation is ongoing.
West Sussex Fire and Rescue Service (WSFRS) crews were also called to the scene in response to a fire, which police believe was connected.
A WSFRS spokesperson said: "On Saturday night three fire crews assisted Sussex Police with an incident at Brimstone Road in Lancing.
"There were reports of fire at a property, but fortunately the fire was out upon arrival, and the incident was left with Sussex Police."
5. Teenager bailed after man, 21, injured in Lancing 'stabbing'
Teenager bailed after man, 21, injured in Lancing 'stabbing' Photo: Sussex News and Pictures