Police arrested a woman after she struck a man with a beer mug at a bar in Haleiwa.

The assault occurred at the establishment on Kamehameha Highway at about 9:45 p.m. Thursday.

Police said the victim, an acquaintance of the woman, sustained a one-inch laceration to his head. The victim drove himself to a hospital where he was treated for his injury.

Police arrested the suspect on suspicion of second-degree assault.