Police have closed the eastbound carriageway of the A55 near St Asaph after a collision left a tractor overturned.
The crash involved a tractor, a van and a trailer.
Two fire engines from Rhyl and Holywell are at the scene. The Wales Air Ambulance was also called to attend
A spokesperson for North Wales Police said: "We were called at 12.13pm to reports of a road traffic collision involving a tractor, van and trailer.
"The eastbound carriageway is still closed near Rhuallt.
"Helimed were also in attendance."
A spokesperson for North Wales Fire and Rescue said: "We were called to a road traffic colliision on the A55 near St Asaph.
"We responded with two engines from Rhyl and Holywell."
A Welsh Ambulance Service spokesperson said: “We were called today (Friday June 16, 2017) at approximately 12.15pm to reports of a road traffic collision on the A55 near to junction 28 involving a van and a tractor.
"Two adult patients were treated at the scene before being taken to Glan Clwyd Hospital, Bodelwyddan.”