Collisions occurred within an hour of each other.
Two young men were killed in separate road traffic collisions in Dublin and Cork on Saturday.
The first happened near Donabate in Dublin after 9pm, the second in Skibbereen in Cork barely an hour later.
Gardai are appealing for witnesses or camera footage from both of these scenes.
The first incident involved a motorbike and a car at the junction of Hearse Road and Cobbe's lane near Donabate in county Dublin.
A man in his early 20s, who was travelling on the motorcycle, died at the scene.
His remains have been removed to Connolly Hospital in Blanchardstown for a post mortem to take place.
Gardaí were alerted to the crash in Skibereen shortly before 10.30pm involving a 4x4 and a car.
The driver of the car, a man in his mid-20s, was pronounced dead at the scene and his body has since been taken to Cork University Hospital where a post-mortem examination will be carried out.
The driver of the 4x4, a man in his 40s, was also taken to CUH for treatment but his injuries are not thought to be life-threatening.
Gardaí said the scene has been preserved for a technical examination, with local diversions in place.
Witnesses of the collision are being asked to contact Clonakilty Garda station o 023-882 1570, the Garda Confidential Line on 1800-666 111, or any Garda station.

Only 65% Of Under 35s Recognise Risks Of Driving Morning After Drinking, As Bank Holiday Approaches
Worst Prison Overcrowding In History Of State, According To Prison Officers Association
Over 12,000 Defects Remain On New National Children's Hospital project.
Minister Martin Heydon Speaks As Fuel Scheme Announced
Sallins Man Part Of Intercepted Global Sumud Flotilla
One In Seven Households Unable To Afford Adequate Home Heating
Fifth Arrest Made In Connection With Fatal Edenderry Fire
Two People, Including A Teenage Boy, Arrested After Gun Incident In Ballymun