JILIN, December 18, Xinhua -- Traces of wild Siberian tigers have been spotted in forest farms in northeast China's Jilin Province, marking the expansion of the tigers' range of activity, the local forestry administration said Thursday.

thumb Forest Public Security -12.19 Wild Siberian tigers spotted in NE China

A wild Siberian tiger is caught by camera in northeast China's Jilin Province on Dec. 10, 2015. [Photo/Xinhua]

Infrared cameras showed footprints and pictures of the tigers in areas administered by the Tianqiaoling Forest Administration in Wangqing County and Baishishan Forest Administration in Jiaohe City last Thursday and Friday, according to the provincial forestry department.

"The Siberian tigers once wandered in Tianqiaoling area but became extinct in the mid 1980s," said Wu Zhigang, a researcher with the provincial academy of forestry.

"The comeback of the tigers shows that they are expanding their sphere of activity from the border areas to the inland regions," he said.

The provincial forestry department set up about 1,000 far infrared cameras to monitor the activity of the Siberian tigers and leopards since 2006. There are 27 Siberian tigers currently living in Jilin Province, according to the latest survey.

Jilin has banned commercial logging in key state-owned forest farms since April 1 this year, which improves the living environment for the Siberian tigers.

Siberian tigers are among the world's most endangered species. They mostly live in northeast China and eastern Russia.