A man's in a critical condition at Beaumont Hospital after being hit in the head by a scrambler motorbike in Dublin.
It happened at Darndale Park in Coolock on Saturday afternoon at around 2.00pm.
The 39-year-old man and a woman were sunbathing when the scrambler motorcycle drove over a hill and hit the couple.
He received serious head injuries.
A 16-year-old teenager is assisting gardaí with their enquiries.
Investigating gardaí are appealing to any person who may have witnessed this incident - or who may have information - to contact Coolock garda station on 01-666-4200, the Garda Confidential Line at 1800-666-111 or any garda station.
Sinn Féin Dublin City Councillor Larry O'Toole says the council needs to do more to help locals who are being tormented.
"Well they have to secure the park - we've tried all that, we've put different gates on the park and all to stop motorbikes and horses all getting into the public park.
"But it being a public park, obviously you can't close it off altogether".