Two children were airlifted to Alder Hey hospital after a car flipped on its roof on the A55 in North Wales.
Air ambulance crews rushed to the scene on the westbound carriageway of the motorway at around 8.30am on Wednesday.
Two people were flown to Alder Hey Children's Hospital following the one-vehicle crash, while the other victim was transported by road ambulance to Ysbyty Gwynedd Hospital in Bangor.
Their conditions have not been disclosed, reports North Wales Live.
The westbound carriageway of the road has been closed as a result of the crash, with one lane of the eastbound carriageway also shut.
A Welsh Ambulance Service spokesman said: "We were called at approximately 8.32am to reports of a road traffic accident involving a single vehicle on the A55 near Abergwyngregyn .
"We responded with two emergency ambulances and our crew was supported by the Wales Air Ambulance .
"One patient is being transported by road ambulance to Ysbyty Gwynedd Hospital, Bangor and two patients are being transported by air ambulance to Alder Hey Children’s Hospital, Liverpool.”
Motorists were urged to avoid the area following the one-vehicle crash this morning.
On Twitter, North Wales Police said: "The A55 is closed westbound following an RTC at Abergwyngregyn.
"One lane of the eastbound carriageway is also shut.
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"There are long delays westbound from J12 Tal Y bont – J14 Llanfairfechan.
"Please avoid area and use alternative routes. Thank you for your patience."#Huge delays built up as a result of the crash.
The road reopened at around 10.10am.
