Indonesian oil and gas workers are on high alert after a Sumatran tiger was spotted inside their mining operation in Riau, Indonesia. <br /><br />Security officers were patrolling the PT BOB PT BSP Pertamina Hulu site in Siak Regency when they spotted the big cat which is said to be a 2-year-old which has become separated from its mother. <br /><br />Sumatran tigers are listed as "Critically Endangered" on the IUCN Red List. <br /><br />There are thought to be not more than 679 individuals living in the wild.
