Gardaí investigating the wounding of two men in a gun attack at the monthly Smithfield Horse Fair in Dublin have arrested a man in his 40s.
The two who were shot are from the same family and from Co Offaly.
As bystanders tried to get away during the shooting, groups of men attacked each other with sticks, tyre irons and other weapons.
A third man was taken to hospital with non-life threatening injuries.
The Army Bomb Disposal Team was called to the area after the discovery of the homemade shotgun, which was made safe and handed over to gardaí.
In a follow up search at Oliver Bond Flats, gardaí recovered a handgun which they believe was dumped there following the violence.
Gardaí believe that 4,500 people turned out for the monthly horse fair, which is the biggest of the year and attracts people from all over Ireland and the UK.
They feared there would be trouble and wanted the fair cancelled because too many people were expected in a small area.
Dublin City Council has also tried but failed to overrule the right to hold the Fair in Smithfield.
Gardaí believe the trouble relates to an ongoing Traveller feud.