BBCThe A5 is closed at its junction with the Woodend Road, Strabane and Leckpatrick Road, Ballymagorry.
Local diversions are in place and signposted.
The Northern Ireland Ambulance Service (NIAS) said they received a 999 call at 00:39 BST about an incident in the Victoria Road area of Ballymagorry.
Two ambulances were dispatched to the incident and one person was taken to Altnagelvin Hospital, NIAS added.
The PSNI said the road was likely to be closed for some time and an update will be provided in due course.
West Tyrone MLA Daniel McCrossan urged motorists to seek alternative routes.
“The A5 remains closed this morning at Ballymagorry. It is not possible to pass through the village,” the SDLP MLA said.
He added: “This is a very serious incident and will take time.”
