A brother and sister and a young man have died in a two-car collision in Co Tyrone.
The collision took place at about 12.30am on Saturday, about a mile outside Strabane near the Co Donegal border.
The dead have been named as Eamonn Sweeney (11) and his 13-year-old sister Emma. Also killed was Jonathan Miller (18), who was in the other car.
The mother of the Sweeney children and a younger son were also taken to hospital, but their condition is not thought to be life-threatening.
The accident happened near Victoria Bridge, which is on the Fyfin Road between Strabane and Castlederg, Co Tyrone, where the Sweeney family lives.
The PSNI kept the road closed for investigation throughout most of Saturday.
The families of the dead have appealed to be left to grieve in private, while police have asked for anyone with information to come forward.
Seven people have died on the roads in Northern Ireland in the first three weeks of 2008.
Five children died on the roads last year.
Saturday's fatalities mean that 40 per cent of that total has been reached already this year.