This Side of Hell — Robert Charles

Corporal David Canning buried his best friend below the burning African sand. Then he was alone, with a bullet-sprayed ambulance containing five seriously injured men and one hysterical nurse in his care. He faced heat, dust, thirst and hunger; and somewhere in the area roamed almost two hundred blood-crazed tribesmen led by a white mercenary with his own desperate reasons for catching up with the sole survivors of the massacre. But Canning vowed that he would win through to safety.