A 45-year-old woman is in hospital after having been injured by an object thrown during an argument which also involved two men.
The police said the incident happened shortly after midnight at a residence in St Paul's Bay.
It involved the woman, who is Hungarian, a 43-year-old man from Slovakia and another man, 26, from Macedonia.
The police said the 26-year-old appeared to have thrown a hard object at the other two and hit the woman. He has been arrested.
The woman's injuries were described as serious.