By Eva Xiao

HONG KONG -- For app users in the world's most populous country, the world's biggest seller of fast fashion has effectively ceased to exist.

As of Thursday, Hennes & Mauritz AB's H&M had been wiped off China's leading e-commerce, ride-hailing, daily-deals and map applications, as Chinese consumers continued to rage over the Swedish clothing brand's decision to stop sourcing from China's Xinjiang region.

H&M's swift erasure from Chinese platforms marked an escalation in the kind of retaliation Western companies can face when running up against Beijing on hot-button issues, such as human rights and China's policies toward ethnic groups in Xinjiang -- and how quickly and massively a backlash can hit a company in one of its most important markets.

Criticism of H&M -- including calls for boycotts -- by Chinese social-media users surged on Wednesday, apparently over the company's statement last year that it was no longer sourcing from Xinjiang, a major cotton producer, because of forced-labor allegations there. The statement suddenly went viral on China's Twitter-like Weibo, amplified by mentions in multiple state-media accounts.

On Thursday, ordering a car to an H&M store was impossible on Didi, the country's largest ride-hailing app, which didn't recognize the brand as a valid destination. Searching for H&M on multiple Chinese map apps, including Baidu Maps, run by China's largest search engine, returned zero results, as if the clothing company didn't exist despite its more than 400 stores in China.

Shoppers planning to purchase H&M clothing online were also out of luck. Starting Wednesday, searches for H&M's name on platforms operated by China's largest e-commerce companies -- Alibaba Group Holding Ltd., Pinduoduo Inc. and JD.com Inc. -- yielded no results. Multiple Chinese Android app stores appeared to have removed one of H&M's shopping apps.

Didi Chuxing Technology Co. and Baidu Inc. didn't respond to a request for comment. Alibaba, Pinduoduo and JD.com also didn't respond to requests.

H&M said on its Weibo account on Wednesday that it followed international guidelines for supply-chain sustainability and that it was "committed to long-term investment and development in China." It didn't immediately respond to a request for comment on Thursday about its disappearance from Chinese apps.

Chinese social-media users also have turned their ire on other international brands, including Nike Inc. and Adidas AG, which had issued similar statements about forced-labor concerns in Xinjiang, but only H&M appeared to be the subject of an across-the-board removal from apps.

"What we are seeing goes way beyond what has been done in the past," said James McGregor, chairman of public-affairs firm APCO's Greater China region. Beijing and many Chinese people feel the world is "ganging up against them so they want to hit back hard," he said.

"I think we will see more of this taking place as China seeks to use commercial pressure to get foreign governments to tone down and back off, " Mr. McGregor added.

In H&M's statement, published in September, the company had expressed concern about reports of forced labor and discrimination against mostly Muslim minorities in China's northwest Xinjiang region, where the Chinese government has built a network of internment camps. Rights groups have alleged that some former camp detainees have been sent to work in factories.

It couldn't be determined why the company faced the sudden onslaught over comments it had made in the past.

Beijing has denied all allegations of human-rights violations in Xinjiang. At a daily news briefing on Thursday, Chinese Foreign Ministry spokeswoman Hua Chunying said allegations of forced labor being used in Xinjiang were "malicious lies" made up by "anti-China forces." If companies decide not to use Xinjiang cotton, it is their loss, she said.

On Chinese social media, postings overwhelmingly supported Beijing's stance.

"Earn a huge profit in China while slandering China...these kinds of enterprises have no basic business ethics," wrote state broadcaster CCTV on Weibo, in a post that was forwarded more than 40,000 times by Thursday.

Such behavior will only result in Chinese consumers "voting with their feet and teaching unruly companies a lesson by boycotting," said CCTV, which has also interspersed criticism on foreign brands with positive images of Xinjiang's cotton fields in its Weibo newsfeed.

Like H&M, which lost two of its Chinese brand ambassadors on Wednesday, other brands saw their celebrity endorsers sever ties over the online outrage, including Chinese actress Tan Songyun, who had been collaborating with Nike.

"The interests of the motherland are above all else," said Ms. Tan's studio on its official Weibo account on Thursday. "We are firmly opposed to all evil conduct that discredits and spreads rumors about China."

Chinese celebrity endorsers for several other brands, including Nike's Converse and Adidas, also walked away after the companies were identified as having opted out from sourcing in Xinjiang or as members of the Better Cotton Initiative, a nonprofit organization that has halted its certification of farms in Xinjiang.

Nike and Adidas didn't respond to requests for comment.

Chinese consumers don't believe the rights-abuse allegations made by the U.S., said Qing Wang, a professor at Warwick Business School. "No brands are immune to this growing tension between the demand of the Chinese consumer and the pressure of Western governments," said Ms. Wang, who has consulted for companies in the U.S. and China.

The barrage against international brands follows escalating tensions between China and Western governments over Beijing's policies in Xinjiang. Earlier this week, the Chinese government announced sanctions on more than a dozen individuals and entities in the European Union, after the European bloc imposed sanctions on four Chinese officials for human-rights abuses in the northwest region.

Washington has also blacklisted multiple Chinese companies over the region's human-rights violations. In January, U.S. Customs and Border Protection instituted a ban on all tomato and cotton products from Xinjiang, which accounts for 87% of China's total cotton production, according to official figures from 2020.

As the list of companies being criticized grew well beyond H&M, some Chinese consumers were reluctant to boycott their favorite brands.

"Almost all of the brands I often wear have stepped on mines," wrote a user on Weibo. "What should I wear in the future?"

Write to Eva Xiao at eva.xiao@wsj.com

Corrections & Amplifications

This article was corrected on March 26, 2021 because the original incorrectly said H&M operates 400 stores. The company operates more than 400 stores in China.

(END) Dow Jones Newswires

03-25-21 1417ET