The incident happened around 11.15 last night
Four people have been hospitalised after a two vehicle collision in Kildare last night.
The incident happened at around 11.15pm on the Sallins By-Pass in Castlesize.
Two men aged in their 40s and 70s, in the first vehicle, were removed from the scene to Mater Misericordiae University Hospital in Dublin where they remain in critical condition.
A young man and woman in their 20s, in the second vehicle, were removed from the scene to The Tallaght University Hospital and remain in serious but stable condition.
The road is currently closed and local diversions are in place.
Gardaí are appealing to anyone who may have witnessed this collision to come forward.
They are also appealing to road users who were travelling on the Sallins By-Pass between 11p.m. and 11.30p.m. with camera footage (including dash cam), to make it available to them.
Anyone with any information can contact Clane Garda Station on 045 868 262, the Garda Confidential Line on 1800 666 111 or any Garda Station.