As the Beijing-backed press continued to wring its hands over close ally North Korea in the wake of Tuesday's nuclear test, online commentators and rights activists said they see the test as a threat to China.
Beijing-based rights activist Hu Jia said on Wednesday via Twitter that the test, the third in defiance of United Nations resolutions, was a humiliation for China's policy towards North Korea.
"Being the big brother to such a little brother has brought China to this pass," Hu wrote, in a reference to popular characterization of the bilateral relationship.
"Who is going to feel the humiliation, if not the Chinese Communist Party?"
He said the underground blast—which was conducted less than 60 miles (100 kilometers) from the Chinese border—was "right in the chicken's mouth," referring to the chicken-shaped map of mainland China.
In a later interview, Hu hit out at China's policy on the Korean peninsula, including its decision to fight alongside the North during the Korean War (1950-1953).
"The price we have paid is too high," Hu said. "As a Chinese citizen, I must express my concern and my outrage at this incident."
Hu said he had called the North Korean embassy in Beijing on Tuesday, after netizens passed around the contact details on Twitter-like sites.
"The first time they said they didn't speak Chinese; and the second person could barely be bothered to speak to me and was even rude," he said.
Protesting radiation
Some netizens expressed concerns that radiation from the latest test explosion could affect northeastern China.
An activist from the eastern city of Hefei, known online by his nickname "we_are_not_a_rabble," said he was briefly detained after he walked through a park in the city holding a placard protesting nuclear testing by North Korea.
"My father and other relatives live in the northeast, but this nuclear test right next to the region will cause pollution," he said.
"I cannot accept or allow this to happen."
He said the authorities had told him that ordinary Chinese citizens shouldn't concern themselves about North Korean nuclear testing.
"[They] just used a bunch of bureaucratic jargon, and basically said I should trust the Party and government and stuff like that," he said.
Meanwhile, Heilongjiang-based lawyer Chi Shusheng said the North Korean regime had already "polluted" northeast China with its drug trade.
"When is North Korea going to stop polluting the three northeastern provinces with its nuclear weapons tests, too?" he wrote via the microblogging service Sina Weibo.
"[China] must immediately stop all aid to this rogue state and its hoodlums," he said.
'Dragging China down with them'
Retired Nanjing University professor Sun Wenguang agreed that China was under threat from the test.
"If this was a nuclear test, then the intentions are evil, because it was very close to China," said
"They want to drag China down with them, to join them in opposition to U.S. interference in North Korea," he said.
"I think that's what they are about; they didn't dare to set it off right near the 38th parallel." Sun said. "Instead, they tested it right near the border with China, which they see as having their backs."
Sun said Beijing's continuing support for Pyongyang had made such an attitude viable for North Korea.
"The unbridled arrogance we have seen from North Korea in recent years has been the result of China's support," Sun said.
Tremors felt in Jilin
The detonation, which set off powerful seismic waves, was audible in some parts of the northeastern province of Jilin, residents said.
One resident of Hunchun city near the North Korean border surnamed Zhuang said she had felt tremors from the test early on Tuesday morning.
"It was like a rumbling and a shaking, early [Tuesday] morning," Zhuang said. "It didn't go on for very long."
Netizens hit out at the test, which came on a public holiday, as the country welcomed in the Chinese Year of the Snake with family celebrations and festivals.
On China's popular microblogging service Sina Weibo, writer @wuqiusanren sent out a tweet asking the question that many echoed.
"Who was this test intended to threaten?" he wrote. "They can't get it as far as the U.S., they haven't got much of an account to settle with Japan, and South Korea shares the same culture and ancestry as them."
"What can they possibly intend other than to threaten China?"
'Psychological threat'
Sichuan-based technology expert Pu Fei said reports had described the device as being about level with those used by the United States at the end of World War II.
"If that's the case, then there is no serious competition here, just a psychological threat," Pu said.
"China also has ways of dealing with rogue states like this," he said.
"But I think this will have the effect of putting [Pyongyang] on the back foot internationally, and that the threat won't have the intended effect."
Formal rebuke
China’s foreign minister on Tuesday called North Korea’s ambassador in to show its displeasure and demanded that Pyongyang cease further threats, a statement on the ministry's website said.
Yang Jiechi delivered a “stern representation” to Ji Jae Ryong, expressing China’s “strong dissatisfaction and firm opposition” to the test.
"Yang Jiechi demanded that the Democratic People’s Republic of Korea side cease talk that further escalates the situation and swiftly return to the correct channel of dialogue and negotiation,” the statement said.
If Ji made any response, it went unreported.
Yang said Beijing wanted a nuclear-free Korean Peninsula and called for a return to long-stalled six-party denuclearization talks involving North Korea, China, the United States, South Korea, Japan, and Russia.
The ministry also called on North Korea not to "take additional actions that could cause the situation to further deteriorate."
Several Beijing-backed media organizations reiterated the ministry's statement in editorials on Wednesday.
The official Xinhua news agency warned in a commentary that Beijing "was losing patience" with North Korea.
Cutting aid to North Korea was one option, the agency said.
"North Korea's third nuclear test is expected to pressure Beijing into getting tougher with its recalcitrant neighbor," it said.
Meanwhile, the Hong Kong-based Wen Wei Po newspaper, which has close ties to China's ruling Communist Party, warned that Sino-North Korean friendship should not be allowed to become a burden on Beijing.
However, Beijing has stopped short of announcing any concrete plans to punish Pyongyang.
Reported by Xin Yu for RFA's Mandarin Service and by Lin Jing for the Cantonese Service. Translated and written in English by Luisetta Mudie.