One man was taken to hospital following a collision this afternoon on the Castlebar side of Pontoon.
A jeep and bicycle collided at about 3.30pm.
Gardai, ambulance and fire personnel attended the scene, and the driver of the jeep was taken to hospital.
Gardai have confirmed that the road is closed, and will remain closed for the rest of this evening and tonight.
Meanwhile, the emergency services are also attending the scene of a road traffic accident in Louisburg.
The 2-car collision occurred on the Westport side of Louisburg.
Both drivers were taken to hospital but their injuries are not believed to be life-threatening.
The road is closed to traffic but Gardai expect it will reopen later this evening.