A garda sergeant has escaped with minor injuries after a car ploughed into him while he was investigating a road collision.
The officer, in his early 40s and based at Waterford, was attending the scene of a minor crash in the city when a man jumped into one of the cars involved and drove at him.
The sergeant was thrown onto the bonnet of the Audi car and dragged along for several metres before falling off onto the roadside near St Herblain Park.
It is understood he suffered cuts and bruises to his arms and body.
Garda colleagues chased the Audi and later arrested an 18-year-old man.
The suspect is being held at Waterford garda station where he is being questioned about the incident.