A 35-year-old man from San Ġwann was grievously injured on Wednesday following an argument in Marsaxlokk.
The police said it was informed that a man was full of blood was on the ground near tas-Silġ Chapel at 11.20pm.
The man had been on site with another when they started arguing and the aggressor allegedly slashed the victim's face before stealing the victim's bag and leaving the site.
A medical team assisted the victim on site and he was then later transferred to Mater Dei Hospital by ambulance.
The police searched for and found the aggressor, a 30-year-old Libyan who lives in Tarxien.
He was arrested and is being held at the police headquarters in Floriana.
An inquiry is being held.