Gardaí and emergency services are currently at the scene of a serious crash on the N14 between the Dry Arch and Polestar roundabouts in Letterkenny.
The collision, between a motorcyclist and a tractor, occurred at approximately 4.55 pm, according to the Garda Press Office.
Both drivers are currently receiving medical attention at the scene.
The two inbound lanes of the road are closed and local diversions are in place.
As a result, there is serious traffic congestion and motorists are being advised to avoid the area.
No further details are available at this time.