Emergency services remain at the scene of a three-vehicle RTC on the Old Ballynahinch Road near Lisburn.
It is understood there are a total of six casualties with three transferred to hospital thus far including a young girl believed to be 12 years old.
A PSNI spokesperson said "The Old Ballynahinch Road and Saintfield Road outside Lisburn is currently closed due to a road traffic collision. This is from the Saintfield Road roundabout to the Comber Road junction. Motorists are advised to take another route for their journey."
