China's state propaganda machine swung into action on Monday to dampen online comments after Beijing condemned North Korea's sixth and most powerful nuclear test on Sunday, which the isolated state said was of an advanced, "missile-ready" hydrogen bomb.
"Shut down all comment across the board on the North Korean announcement that [supreme leader] Kim Jong Un ordered a hydrogen bomb test, and related news items," the ruling Chinese Communist Party's propaganda czars said in a directive to news editors leaked and posted online by the U.S.-based China Digital Times website.
"All websites are banned from deliberately hyping related topics," the directive, which was likely transmitted verbally to news editors across China, said.
Directives regarding permissible news content may be issued by the State Council press office, the powerful Cyberspace Administration, the State Administration of Press and Publications, Radio, Film and Television (SAPPRFT), and the culture ministry, among other agencies.
North Korea said in a televised announcement on Sunday that the underground nuclear explosion, which registered on international seismic agencies as a human-generated earthquake, was a "perfect success."
China said it strongly condemned the nuclear test and urged Pyongyang to stop its “wrong” actions, while President Xi Jinping and Russian President Vladimir Putin said they would "appropriately deal" with North Korea’s nuclear test, Xinhua news agency reported.
Chinese residents near the border with North Korea said they felt a "huge tremor" that lasted for less than a minute.
"Actually we have no idea [if this was the nuclear test], but the tremor went on for not quite a minute," a resident of Changbai county surnamed Zhang told RFA. "It has already been announced online that it was a 6.3 magnitude earthquake."
A second resident of Changbai, in the northeastern province of Jilin, close to the North Korean border, said rumors immediately began to fly that the tremor was a North Korean nuclear test.
"Some people were saying it was North Korea testing a nuclear weapon, while others said it was an earthquake," the resident said. "All of the bowls and chopsticks fell off the table."
'Very strong tremor'
An official who answered the phone at the Changbai county emergency response team confirmed the reports.
"There was a very strong tremor here, a very distinct one," the official said. "We have contingency plans, which have been put into place all along the border area."
China's State Nuclear Security Administration said it had begun nuclear radiation testing as part of emergency contingency plans in China's three northeastern provinces and the eastern coastal province of Shandong, which faces the Korean peninsula across the Yellow Sea.
Wu Fei, senior fellow at the Chinese public diplomacy and international relations think tank Chahar Institute, said the timing of the test seemed to be designed to embarrass Beijing, which is hosting the leaders of emerging economies Brazil, Russia, India, and South Africa in Xiamen this week.
"China is currently hosting the BRICS economic summit, and I think this nuclear test is intended to remind the leaders of China and Russia that they need to be discussing the North Korean nuclear issue at that summit," Wu said. "China's notion of the denuclearization of the Korean peninsula is only a target, basically."
"[China] is trying to deal calmly with it, and not give [North Korea] any recognition."
Wu said North Korea wants to be "taken seriously." But he said the likelihood of that happening in Beijing was "not very high."
The bomb was designed to be mounted on a newly developed intercontinental ballistic missile (ICBM), Reuters cited Pyongyang as saying.
Washington has warned of a “massive” military response if the U.S. or its allies are threatened.
“Any threat to the United States or its territories, including Guam or our allies will be met with a massive military response, a response both effective and overwhelming,” U.S. Defense Secretary Jim Mattis said after a meeting with President Donald Trump and his national security team.
President Donald Trump has also mooted the idea of cutting off trade with North Korea's trading partners, which would include China.
'Join forces to curb North Korea'
But Xia Ming, a political science professor at the The City University of New York, said China, Russia and the U.S. need to work together.
"No country has a hope of resolving this on their own," Xia said. "And if the U.S. hopes to bring China and Russia on side, it'll have to be ready to make some concessions."
"The only effective way to deal with this is for the three countries to maintain a three-way dialogue on the North Korean problem, and join forces to curb North Korea," he said.
Retired Toledo University professor Ran Bogong said such concessions might include a temporary halt to joint military exercises between South Korea and the U.S., a suggestion which Beijing has already put forward. Washington and Seoul are unwilling to do this.
"A halt to joint military exercises for one year could be offered in return for a temporary halt to North Korean nuclear tests," Ran said.
"That way, both sides would be able to cool off and return to the negotiating table."
"A delay of a year wouldn't hurt ... and if the talks didn't work, neither side would have much to lose."
He said the failure of previous years of six-party talks "doesn't mean necessarily that talks now would fail."
A resident of Baishan county surnamed Li said he doesn't expect a resolution to the issue while the current regime remains in power in Pyongyang, however.
"This evil will remain forever, unless the North Korean government falls, because their whole economic and strategic policy relies on their having an enemy," the resident said.
"They also need to make the [North Korean] people feel that their country is very powerful."
Reported by Wong Siu-san and Dai Weisen for RFA's Cantonese Service, and by Yang Fan and Gao Shan for the Mandarin Service. Translated and edited by Luisetta Mudie.