A surfer was seriously injured Thursday in Sydney's second shark attack in two days, police said. A 33-year-old man, whose name was not released, was taken to a hospital with "severe injuries" to his left arm after the attack off Sydney's central Bondi Beach, a state police statement said. Others surfers helped him to shore. His condition was serious, police said. A Navy diver fought off a shark Wednesday in the harbor, but his hand and a leg were badly mauled.