A truck has caught fire closing off a section of the Pacific Highway north of Harwood early Saturday morning.

The B-double semi-trailer was carrying a load of alcohol northbound when a broken bearing caused the fire to start.

The fire engulfed the cabin of the vehicle, and emergency services were called onto the scene to extinguish the blaze.

One northbound lane of the Pacific Highway is still closed to traffic as salvage operations are expected to take through to the middle of the day.

It is unknown if there were any injuries from the fire.

Meanwhile, in a three vehicle collision at Tyndale yesterday, the driver of a semi-trailer was taken by ambulance to Coffs Harbour Health Campus with possible internal injuries.

Police say they believe the truck collided with the rear of an Isuzu work van, pushing the van sideways across the road.

The van then clipped a caravan, causing the car and caravan to jackknife in front of the other two vehicles.

The highway was closed for approximately two hours northbound to remove the vehicles.

The Westpac rescue helicopter was called but was not required to transport any patients.