Chinese social media users berated authorities for their relatively mild response to North Korea's widely condemned nuclear test, likening Pyongyang to a "crazy dog" that had humiliated Beijing.
The aggression toward China's defiant neighbour contrasted with the official response from Beijing—expressing "firm opposition" but reiterating calls for calm and restraint and not mentioning any reprisals or sanctions.
Pyongyang conducted the test on Tuesday, two days after the Lunar New Year which is China's biggest annual festival, and as the public holiday continued.
"If you pursue an unjust long-term diplomatic policy, then people will dare to explode a stinkbomb at your door while you are on holiday," said Yu Jianrong, a director at the Chinese Academy of Social Sciences.
"You are inviting your own humiliation," he added on Sina Weibo, China's hugely popular Twitter-like service.
China is North Korea's most important backer, providing it with trade and aid that have enabled the state to survive for decades since the end of the 1950-53 Korean War.
In a commentary China's official Xinhua news agency said the explosion was an attempt by a "desperate DPRK" to keep a perceived external threat at bay.
Beijing fears instability would bring refugees flooding across the border, a US-led escalation in the region or even ultimately a unified Korea with a US military presence next door.
But an online commentator using the handle Wuyuesanren slammed the idea that North Korea's nuclear programme boosted China's security, likening Beijing's policy to "keeping a crazy dog to guard the house".
North Korea "simply doesn't trust China and is not willing to be inhibited by China", wrote Weibo user Zhuanshengben. "For China alone to emphasise China and North Korea's so-called friendship, this is the ultimate stupidity."
Another user called Long Can declared that "if America mobilises troops against North Korea, I will give its government my entire year's salary".
Meanwhile on Twitter—which is blocked in China—one of the country's most prominent dissidents, Hu Jia, called it and North Korea "the most despicable big rogue and ruthless little rogue".
He posted a recording of a phone call he said he made to the North Korean embassy in Beijing, in which he told them: "I just want to say, I am Chinese citizen Hu Jia, and I want to express my opposition to your carrying out a nuclear test."
"What?" came the response from the embassy. "Are you out of your mind?"
Explore further: Facebook goes retro with 'Rooms' chat app