Police have closed the A21 Newtownards – Bangor carriageway in both directions following a three vehicle road traffic collision.
Traffic is being diverted at the Rathgael Road and Green Road.
Motorists are also cutting through Conlig to avoid the scene.
Paramedics and local fire crews are at the scene.
Delays are expected in the area.
A source told Belfast Daily: “We understand one person has died but we are awaiting confirmation.”