A 16-year-old boy has been released without charge after being questioned in relation to online threats against teaching staff at a north Co Dublin secondary school.
A file has been prepared for the Director of Public Prosecutions.
The school notified parents not to bring their children to the school today following the gun-related threat, which circulated last night on social media.
Gardaí were alerted and the teenager was arrested and questioned at a Dublin garda station.
Gardaí are liaising with management at the school and are satisfied that there is no imminent danger to staff or students attending the school.
Dublin and Dún Laoghaire Education and Training Board confirmed that the school was shut as a "precautionary measure", but is expected to re-open tomorrow.