Gardaí from Charleville had responded to a call about a number of people involved in a street fight at the town’s Brindle Hill Estate.
Further back-up was required after they arrived at the scene at around 3am to discover about 20 men, some armed with what Gardaí described as “implements”.
Superintendent Pat McCarthy said reinforcements arrived from Mallow and Bruff, Co Limerick.
Members of the armed Regional Support Unit (RSU) also arrived from Cork.
Superintendent McCarthy said a number of people fled when gardaí first arrived, but others continued fighting.
After restoring order, Gardaí had to summon ambulances to take four men with varying injuries to hospital in Limerick.
It is believed those involved in the fighting were members of two extended families who clashed after returning from separate social outings.
A house at Brindle Hill was also badly damaged during the disturbance.
Supt McCarthy said that no arrests were made at the scene.
However, he said Gardaí were keeping a close eye on the situation in case violence flared up again.
Meanwhile, gardaí in Mallow are investigating the stabbing of a man in his late 20s.
At approximately 1.30am yesterday, gardaí were called to a takeaway restaurant in the town where they found a man bleeding profusely from stab wounds.
The man had reportedly been attacked with a knife and a screwdriver.
The injured party, originally from Ballyphehane in Cork city, was taken to Cork University Hospital where he was treated for wounds to his stomach, left hand and a finger.
Gardaí are investigating if the stabbing took place earlier at Granary Court in Mallow.
Anybody with information is asked to contact Mallow Garda Station at 022-21105.