Farshad Firooznia, head of DOE’s Firuzkuh office, said the big cats were spotted in the no-hunting mountainous areas of Kaveh Deh.

The official noted that park rangers have spotted several Persian leopards in the region during the past couple of months, raising hopes that the number of rare species may be increasing in the region.

Persian leopards are among the most endangered species in the world. The animal has been listed as "endangered" in the red list of the International Union for Conservation of Nature. Iran is one of their main habitats.

Reduced prey population and shrinkage of their natural habitat are threatening the big cats. Bamou National Park in the southern Fars province is one of the main habitats of the Persian leopard.

Middle Zagros, a part of Zagros Mountains straddled across Iran, Iraq and southeastern Turkey, are the main habitats of Persian leopards.