A 31-year-old man is in a stable condition in hospital after being stabbed in the abdomen.
The incident happened during an attack in Moy, Co Tyrone.
Two other men, aged 27 and 33, were treated in hospital after being injured in the incident at The Square at about 01:20 GMT on Sunday.
Police said the three men were attacked by a number of men after they had “just left licensed premises”.
Two men, aged 18 and 20, were arrested in connection with the incident.