SHANGHAI -- A group of citizens in a northeastern Chinese city bordering North Korea have taken to the streets protesting the North's latest nuclear test as concerns over radioactive contamination are mounting there, a US broadcaster reported Wednesday.

They staged a protest Sunday against the North's most powerful nuclear test on Sept. 3 in downtown Harbin, Heilongjian Province, shouting, "We strongly protest the test that intimidates the three northeastern Chinese provinces (adjacent to the North)," Radio Free Asia said. 

"No country conducts a nuclear test in border areas, but North Korea poses a grave threat to China by enforcing the nuclear test in a place very close to China," rights activist Yu Yunfeng, who led the protest, was cited as saying.

He underlined that the test triggering a 5.8 magnitude earthquake can affect China's air pollution as the test site, Punggye-ri in the North's Hamkyong Province, is just 36 kilometers from the border between the two nations, the broadcaster said.

The Chinese government carried out radioactive surveys in the Chinese provinces right after the test, and concluded that no noticeable impact had been discovered.

On Thursday, however, it temporarily shut down the southern part of its popular Mount Paekdu tourist site on the border with North Korea for safety reasons. (Yonhap)