Four Syrian men, three of whom were injured during an argument in Qormi, are being detained at the police lock-up in Floriana.
The police said in a statement that officers were alerted about the brawl in Mdina Road on Thursday at around 11.45pm.
Pieces of wood and metal were flung around during the argument.
Three of them were rushed to Mater Dei: a 20-year-old suffered grievous injuries while two 23-year-olds suffered slight injuries.
Together with the fourth man, an 18-year-old, they are being kept in police custody.
Investigations are ongoing.