LANZHOU -- Images of five wild leopards were captured by infrared cameras in Northwest China's Gansu province, suggesting the existence of the rare animal in eastern Gansu.

Leopards are under China's highest national-level protection and are listed as vulnerable on the International Union for Conservation of Nature's Red List of Threatened Species.

A team led by Zhou Tianlin, head of the college of life science and technology of Longdong University, collected the images of leopards in the Guanshan forest zone near the city of Pingliang from July 24 to Nov 20.

Based on the discoveries in Gansu, Shaanxi, Shanxi and Ningxia, the researchers believed that an area between eastern Gansu and northern Shaanxi could be a major habitat of leopards in China, Zhou said.

The Guanshan forest zone had experienced a sharp decline of flora and fauna resources due to human activities since 1950s. After 2000, efforts were made to restore the ecosystem in the region through returning farmland to forests and banning grazing on mountains.

Besides leopards, a variety of wild animals have been spotted in recent years, including wild boars, roebucks, crowned deer and red foxes, according to Zhou.