TOKYO (AFP) - A Siberian tiger mauled to death a zookeeper on Saturday in western Japan who had been trying to encourage the animal to mate, a zoo official said. A horrified visitor to the Kyoto City Zoo reported to management that the 150-kilogramme (330-pound) tiger had pounced on zookeeper Atsushi Ito, an official said. Zoo authorities shot the tiger with a tranquiliser gun and rushed Ito to a hospital, where he was pronounced dead from serious injuries to his head, face, neck and hands. Ito, 40, had been trying to couple the tiger with a three-year-old female tiger. The zoo, the second oldest in Japan, was shut down on Saturday. It has launched an investigation into the incident. In 2005, a white bear attacked and seriously injured another keeper at the zoo.