China rules out radiation from North Korea after nuclear test

China has not detected an abnormal rise in radiation along its borders with North Korea and ended its 8-day emergency monitoring following Pyongyang's most powerful nuclear test to date, the government said today.

China's closest ally North Korea on September 4 carried out a powerful nuclear test, claiming to have developed an advanced hydrogen bomb that could sit atop an intercontinental ballistic missile.

The radiation monitoring, conducted at the northeastern border areas was ended yesterday, a statement from China's Ministry of Environmental Protection (MEP) said.

No abnormal results were showed after eight days of monitoring, the MEP was quoted as saying by the state-run Xinhua news agency.

"A comprehensive assessment has concluded that this DPRK (South Korea) nuclear test has caused no environmental impact on China, and conditions for a termination (of the emergency monitoring) have been met," it said.

All monitoring stations in the border areas and surrounding regions, including the provinces of Heilongjiang, Jilin, Liaoning and Shandong, recorded normal radiation levels as of 6 PM yesterday, according to the MEP.

The ministry said it would switch to routine monitoring after the emergency response ended, conducting automatic radiation monitoring and regular sampling analysis at key border areas.

Some reports earlier said there was marginal increase of radiation in some areas.

Real-time radiation levels recorded at automatic monitoring stations in and near the northeastern border areas will continue to be made public to address people's concerns, the MEP said.

The China Earthquake Administration reported that a magnitude 6.3 earthquake struck South Korea at 11:30 AM on September 4 with an epicenter depth of zero km, saying that it might have been caused by explosion.

The Korea Central Television announced on the same day that the country had successfully detonated an H-bomb, a hydrogen bomb that can be carried by an intercontinental ballistic missile.

The explosion from the most recent nuclear test, the North's sixth, was considerably larger than previous tests and was felt by residents in Chinese cities hundreds of kilometres from the border.

China's Foreign Ministry has expressed firm opposition to and strong condemnation of the test.