It comes after a 22-year-old man from Kent suffered a single stab wound in Highland Road, Southsea, at 11.50pm on September 12.
He was arrested but later de-arrested over the incident.
A 20-year-old man from Southsea, arrested on suspicion of GBH with intent, and two men, 20 and 21, also from Southsea, arrested on suspicion of affray, returned bail yesterday.
Hampshire police confirmed that the men were not charged and face no action.
The morning after the stabbing drops of blood were on the ground outside Kensington Hair in Highland Road, at the junction of St Augustine Road.
Each of the four men involved received treatment at Queen Alexandra Hospital in Cosham.