Elsewhere, a woman in her 20s was killed after she was struck by a car in Loughlinstown in Dublin at around 11.50pm.
The woman, a pedestrian, was pronounced dead at the scene.
Any road users who may have camera footage from the area at the time have been asked to make it available to investigating gardaí.
Anyone with information has been asked to contact Shankill Garda Station on (01) 666 4400, the Garda Confidential Line on 1800 666 111, or any Garda station.
Earlier on Saturday, two men, aged in their 20s and 30s, were killed in a two-car collision on the N15 in Birchill in Co Donegal shortly after 2pm.
Four others, a man and woman in their 20s from one vehicle and a man and woman in their 40s, the another, were hospitalised with non-life-threatening injuries.
Gardaí appealed for witnesses of the incident to come forward and asked road users who may have camera footage, including dashcam, and were travelling in the area between 1.30pm and 2.30pm to make their footage available.
Anyone with information has been asked to contact Donegal Town Garda station on 074 974 0190, the Garda Confidential Line on 1800 666 111, or any garda station.
