The Dark of the Sun by Wilbur Smith
'The bend in the road rushed towards them, just a few more seconds. Then, with a succession of jarring crashes that shook the whole body of the car, a burst of fire hit them from behind. The windscreen starred into a sheet of opaque diamond lacework, the dashboard clock exploded powdering Shermaine's hair with particles of glass, two bullets tore through the seat ripping out the stuffing like the entrails of a wounded animal.'
Bruce Curry is the leader of a mercenary band with the dubious support of three white officers. His mission is to relieve a mining town cut off by the fighting and to retrieve a priceless consignment of diamonds. Ranged against his ill-disciplined unit are bandits, guerrillas and hostile tribes that infest the land. But there is another, even deadlier enemy - one of his own men . . .