Gardaí are investigating after two men were reported entering a manhole near Dublin Castle.
The men were seen climbing down the manhole at about 10pm last night at Little Ship Street. Gardaí were called and preserved the scene, a Garda spokesman confirmed.
A Garda sub-aqua unit is on the scene and gardaí are liaising with the drains department of Dublin City Council.
No break-ins to buildings in the area have been reported, the Garda spokesman added.