Four members of the RUC were injured and five vehicles damaged during a disturbance in the town of Moy on the Tyrone-Armagh border last night.
One of the officers suffered a broken nose and the others bruising after the incident which lasted for about 20 minutes.
An RUC spokeswoman said they were investigating the disturbance which started at 2.45 a.m. and involved up to 30 people. Three men have been arrested.