A torrent of criticism from China's government and people over Malaysia's handling of the search for a missing jetliner is threatening to cast a chill over one of Beijing's closer relationships in a region fraught with geopolitical rivalries.
Since Malaysia Airlines Flight MH370 disappeared three weeks ago, the Southeast Asian country has faced verbal attacks from China's government, media and passengers' families angry at its perceived muddled response and poor communications.
Several Chinese celebrities have now taken up the cudgels on social media, urging their millions of followers to boycott Malaysia, threatening to worsen what seems likely to be a heavy fall in lucrative Chinese tourism.
In Malaysia, China's reaction is increasingly viewed as high-handed, excessively harsh and hypocritical as Kuala Lumpur grapples with what it sees as an unprecedented crisis.
"Do they think they are the only ones grieving over the missing plane?" wrote Malaysian Facebook user Pei Ling Gan.
"I wonder if they would speak up against their government for Tibet and Taiwan in the name of truth and justice, too."
Several high-profile Chinese celebrities, including actress Zhang Ziyi, star of the movie "Crouching Tiger, Hidden Dragon", have lashed out at Malaysia and urged Chinese not to visit.
Grief-stricken relatives cursed and screamed at the Malaysian ambassador and other government and airline officials at news conferences in Beijing this week, accusing them of murdering their loved ones. Most passengers on the flight were Chinese.
Passengers' relatives tried to storm the Malaysian embassy in Beijing on Tuesday and were provided with buses by police afterwards, reinforcing suspicions that China's government has encouraged the outbursts in order to channel discontent over the so-far fruitless search towards Malaysia.
"The relationship between the Malaysian government and the Chinese government is quite strong. So I don't know why they are acting like this, maybe it's convenient," said Nur Jazlan Mohamed, a member of parliament for Malaysia's ruling party.
Chinese leaders have several times "demanded" action from Malaysia, while state-backed media have taken an even harsher line, going so far as questioning Malaysia's ambitions to become a developed country. Social media campaigns have struck a threatening tone, with conspiracy theories gaining popularity.
Analysts say China's leaders are mindful of domestic opinion that expects China to stand up for its citizens' interests abroad with a robustness that matches its growing clout as the world's second-largest economy.
A long-term deterioration of ties is unlikely - both countries have too much to lose from an otherwise thriving economic relationship, analysts said. But the bad blood generated by the crisis could linger, adding to wariness in Malaysia and other Asian nations over China's rising regional power and leadership pretensions.
Beijing has a fraught relationship with many of its Southeast Asian neighbours and is party to a string of territorial disputes, particularly in the South China Sea.
"There's a lot of public relations to be done, a lot of re-engagement. There will be a dramatic dip in the relations in that sense," said Tang Siew Mun, a foreign policy specialist at Malaysia's Institute of Strategic and International Studies.
Malaysian Prime Minister Najib Razak plans to go ahead with a visit to China in May, part of a series of exchanges that had been planned to mark the 40th anniversary of diplomatic ties.
But other events are falling victim to the outpouring of rage against Malaysia.
The Malaysia-China Chamber of Commerce would postpone some events it has been planning to mark the anniversary, said its vice president Tan Yew Sing.
Malaysian Tourism Minister Nazri Aziz said on Monday that "Visit Malaysia Year" roadshows in China would be halted until the MH370 case is closed.
Chinese travel agents have reported a slump in bookings for Malaysia. The China Daily reported on Wednesday that one large travel agency, Beijing-based China Youth Travel Service, had cancelled all existing bookings with Malaysia Airlines.
Malaysia, with a Chinese ethnic minority that makes up more than a quarter of its population, has seen itself as having a special relationship with China ever since it became the first Southeast Asian country to establish diplomatic ties in 1974.
Malaysia's economic and investment ties have never been stronger with China, its largest trade partner. Najib and Chinese President Xi Jinping pledged to triple two-way trade in four years to $160 billion during Xi's visit last year, when he also bestowed coveted "strategic partner" status on Malaysia and announced plans for their first joint military exercises.
"This adverse affect should be short-term," said Tan of the chamber of commerce. "It is not to the advantage of the Chinese government to let this carry on."