A man in his 40s is being questioned by gardaí investigating a gun attack at the Smithfield Horse Market in Dublin yesterday.
He is being held at Bridewell Garda Station.
Two men were injured in the shooting and a third was wounded with a slash hook.
Armed gardaí arrested the man from south Dublin just before 9pm last night in connection with the concealment of a handgun, which was recovered at Oliver Bond Flats.
The gun was recovered along with an improvised shotgun following the violence.
Gardaí have tried to interview the men in hospital, but so far they have not co-operated with the investigation.
Gardaí say the monthly Horse Market is a major drain on resources, including the public order unit, the air support and the mounted unit. The number required to police it was more than nine times the normal ratio for a major public event, they claim.
Dublin city councillors have called on the Government to ban the Smithfield Horse Fair following yesterday's violence.
This follows an emergency motion at this evenings monthly council meeting.
In a statement today council officials said they are powerless to stop the market because of current legislation.
Critics of the market say the violence shows the danger posed by the monthly event which they say is uncontrolled and unregulated.
The DSPCA has called for the market to be shut down with immediate effect, but Dublin City Council says it will require a change in legislation to enable it to do so.
Pavee Point Travellers' Centre issued a statement on yesterday's events expressing 'its shock at and condemnation of the events of violence which occurred'.
'Pavee Point is deeply concerned to ensure that the welfare of animals and people at horse fares is of the highest possible standard,' the statement said.
'It would be a disaster if one, admittedly serious, incident, should end a longstanding tradition for the Smithfield area.
'The Smithfield Horse Fair is a fixture in the city's life, and it would be a mistake to pass up the opportunity to effectively regulate and improve the fair in the interests of the animals, traders and the city', it added.
Gardaí are appealing for witnesses to the shooting.
They are particularly interested in hearing from any person who may have photos or video footage relating to the incident.
Witnesses can contact the Bridewell Garda Station on 01-6668200, the Garda Confidential Telephone Line on 1800-666111 or any garda station.