Sept. 14 (UPI) -- Public access to the Changbaishan National Nature Reserve in China, also known as Mount Paektu in North Korea, has been partly blocked out of safety concerns, according to a South Korean newspaper.
Donga Ilbo reported Thursday that Chinese authorities have temporarily closed parts of the national park in northeastern Jilin Province amid rising fears in the region about radioactive contamination, following North Korea's sixth nuclear test on Sept. 3.
The area that is no longer accessible to the public is located about 70 miles from Punggye-ri, the North Korean nuclear site where Pyongyang recently detonated a bomb that may have released as much as 250 kilotons of energy, according to U.S. experts.
The announcement on the shutdown was posted to Weibo -- the Chinese social network that most closely resembles Twitter -- on Thursday.
"For the safety and convenience of travelers, we have temporarily closed the southern tourist zone of Changbai Mountain," authorities said. "Officials are thoroughly investigating the safety of the tourist area."
Chinese authorities also said the area will remain closed until "the potential risks disappear."
Falling rocks have been causing problems but the northern and western zones of the national park are to remain open, they added.
Chinese commenters said online they fear the worst, following the test.
China had been repairing facilities around Changbai Mountain for four years, and commenters said it is unfortunate the park must close because of North Korea's provocation.
Speculation is rising in China whether falling rocks at the mountain are the result of the test, according to the Donga.
Commenters said the Chinese government was blocking reply messages to the announcement.
The Changbaishan National Nature Reserve is considered the official birthplace of former North Korean leader Kim Jong Il.
The mountain sits on the border between North Korea and China and is accessible from both sides.