Two Gardai were hospitalised after being beaten in Claremorris overnight.
The Gardai – one woman and one man – were attacked after being set upon at Kilcolman Road in the town after being called to an earlier incident in the area.
Both Gardai were treated at Mayo University Hospital and were later released.
A spokesperson for the Mayo Garda Division is reported as saying the attacks were serious and prolonged.
He said that three men had set upon the male officer and the attack had continued on the main road.
Three suspects were later arrested and brought to Castlebar and Westport Garda stations, where they are still being questioned.
Gardai are appealing for witnesses to contact them on 094-93-72080 or on the Garda Confidential Line – 1800 666 111.