Three Columbian men were injured in a brawl in Paceville early on Thursday.
The police said an argument, followed by a fight, took place at 5.30am in St Augustine Street.
It involved mostly workers at the end of their shift.
A 21-year-old was seriously injured while the other two, aged 23 and 35 were slightly injured. All were treated in hospital.
The police are trying to identify the other people involved.
A magisterial inquiry is underway.