China’s environment ministry started emergency radiation monitoring along its border regions in northeastern China on Friday morning after North Korea was suspected of carrying out a fifth nuclear test on Friday.
“Artificial seismic waves” from a 5.3-magnitude quake were detected near North Korea’s Punggye-ri nuclear test site, a South Korean official said.
Pyongyang celebrates Foundation Day on Friday, which marks the anniversary of the founding of the nation in 1948.
Chinese residents living near the border said on social media that they had felt a strong tremor similar in size to when North Korea conducted a nuclear test in January.
A Weibo user named “Scriptwriter Little Six” living in Yanbian Korean Autonomous Prefecture, on the border with North Korea, said he was awakened by a quake at around 8.30am, which sent furniture crashing and shattered windows in his home
He said he was so scared that he immediately jumped out of bed and ran out of his house.
Another Weibo user, living in Changbai Korean Autonomous County, in Jilin province, said she had felt a clear tremor this morning and her first thought was that North Korea had conducted another nuclear test.
“Because this place is not above a seismic belt and has no oil reserves, it must be another nuclear test by [North Korean leader] Kim Jong-un,” she wrote.
Friday’s earthquake is the largest of the four past tremors believed to have been caused as a result of Pyongyang’s nuclear tests.
Previous artificial earthquakes in the same area have all been confirmed later as nuclear tests.
A 4.8-magnitude quake was reported when Pyongyang conducted its fourth test in January.