China border residents evacuated from buildings after N Korea nuclear test: Report

BEIJING - Chinese border residents were evacuated from buildings after feeling tremors from North Korea's nuclear test on Wednesday, state media reported.

People near the frontier with North Korea "clearly felt tremors" on Wednesday morning when Pyongyang said it detonated a hydrogen bomb, state broadcaster China Central Television (CCTV) said on a verified social media account.

The areas on the border included Yanji, Hunchun and Changbai in Jilin province, it added - some of the counties closest to the North's nuclear test site.

Residents in Yanji saw desks and chairs shake for several seconds and some companies evacuated employees from their offices, CCTV said.

Students at a senior high school were dismissed during an examination after its recreation grounds cracked, it added.

China's foreign ministry on Wednesday said authorities were evaluating the environmental impact of the nuclear test, adding currently the radiation level in the area was "normal".

Environmental officials' monitoring showed indicators within normal ranges, foreign ministry spokeswoman Hua Chunying told a regular briefing, so that "so far the nuclear tests have had no impact on the public and health".

China is the North's closest diplomatic ally and main provider of trade and aid, but Beijing has become increasingly frustrated with its pursuit of its nuclear ambitions and regularly calls for calm on the Korean peninsula.

Last month, North Korean leader Kim Jong-Un suggested Pyongyang had already developed a hydrogen bomb, but the claim was questioned by international experts and scepticism continued over Wednesday's test announcement.