A 19-year-old woman and a man in his thirties last night remained critically ill in hospital after separate crashes in Bangor and Dungannon.
Both incidents were single vehicle collisions which happened early on Sunday morning.
The woman was among four teenagers who were taken to hospital after the crash on Bangor’s Ballycrochan Road.
It is believed the 19-year-old was driving when crash happened at about 3:30am.
One of the teenagers injured in the Bangor crash is in a stable condition, another has been discharged from hospital and the condition of the third patient is not known. Their car was a Fiat Grand Punto.
The man is believed to the driver of a vehicle which hit a tree on Moy Road, Dungannon, shortly after 5:00am. He was driving a silver BMW X5.
In both cases police are asking for witnesses or anyone with dash cam footage to contact them on tel 101.