By Rajesh Roy and Shan Li

NEW DELHI -- India banned dozens of Chinese mobile apps, including TikTok, UC Browser and WeChat, citing security concerns for the country's fledgling cyberspace.

The move comes after a recent deadly clash between security forces of India and China near a disputed border in the Himalayan mountains that left 20 Indian soldiers dead.

Rising tensions since then have come with calls in India for the government to retaliate against China in some way.

A senior Indian government official, who declined to be identified, said the measures were undertaken because the apps may have been used for activities to harm the country's defense sector.

"This is India's first salvo to China after the border clashes, showing that India has a diverse range of retaliatory options," said the official.

He said the move could lead to more countries following India to act similarly.

The Ministry of Electronics and Information Technology, calling the issue "a matter of very deep and immediate concern which requires emergency measures," said in a statement that it had received multiple complaints about misuse of some mobile apps for stealing and unauthorized surreptitious transmission of users' data to servers outside India.

"The compilation of these data, its mining and profiling by elements hostile to national security and defense of India...ultimately impinges upon the sovereignty and integrity of India," it said.

UC Browser is a web browsing app from Alibaba Group Holding Ltd., and WeChat is the blockbuster Chinese messaging app from Tencent Holdings Ltd., which has over 1.2 billion monthly active users worldwide. Both have found an audience in Asian countries such as India and Indonesia.

The most popular app banned was TikTok, which is owned by Beijing-based Bytedance Ltd. The video app has been wildly popular with Indian youths and has dominated the social-media landscape along with WhatsApp, which is owned by Facebook Inc.

Bytedance, Alibaba and Tencent couldn't immediately be reached for comment.

Last month, India was the top country for new users of TikTok, accounting for 20% of the app's nearly 112 million downloads around the world, according to Sensor Tower. The U.S. was in second place at 9.3%.

Including TikTok, six of the top 10 most downloaded apps in India were from Chinese tech companies, compared with four from American companies, according to a report published in April by Paulson Institute's MarcoPolo think tank. Chinese firms had just three of the top 10 apps in India in 2015, according to the report.

Analysts see the latest Indian action on Chinese apps as a protective step to push back against encroachment by Beijing.

"The digital war between China and India is hotting up because there is a heavy propaganda element infused with internet based nationalism on both sides," said Sreeram Chaulia, Dean at Jindal School of International Affairs in Haryana State near Delhi.

Mr. Chaulia said India would like to wean its citizens from dependence on Chinese goods and services -- particularly online -- to prevent Beijing from dividing Indian society and weakening New Delhi's resolve to counter China on the border dispute and broader bilateral strategic competition.

"If China becomes indispensable on social media and online consumption habits of Indians, it would soften public opinion in India and confuse Indians as to whether or not China is a major threat," he said.

As China's government grows more combative abroad, other countries' consumers and regulators have responded by putting pressure on Chinese firms or spurning Chinese brands altogether -- particularly its technology players, which have been among the most prominent Chinese companies doing business around the world.

The backlash has been fiercest in India. Outrage over the deaths of 20 Indian soldiers in the border clash with Chinese troops added fuel to a boycott movement that has already seen Indian smartphone users mass-deleting Chinese-made software.

Indian officials already have said they would bar their state-run telecom companies from purchasing equipment from Chinese companies such as ZTE Corp. and Huawei Technologies Co. for future 4G mobile networks. Indian authorities have also privately warned telecom operators against working with Chinese companies in the rollout of new 5G networks. As recently as December, Huawei and ZTE were welcomed to participate in India's 5G trials.

India has been the biggest untapped market for some of China's quirkiest social-media firms who had been signing up hundreds of millions of consumers in the world's second-most populous nation, looking to capture users who weren't hooked on to American apps such as Facebook and Twitter.

Chinese content-sharing apps such as Bytedance's Helo and TikTok have been penetrating deep into the Indian market, where most of the country's 1.3 billion people are getting online for the first time using low-cost smartphones and dirt-cheap data plans.

TikTok is bigger in India than anywhere else outside of China, owing to the South Asian nation's massive population and legions of young and largely unemployed fans. The app was downloaded 611 million times in two years on Apple Inc.'s app store and Alphabet Inc.'s Google Play, according to research firm Sensor Tower. Young people are often found in parks and parking lots shooting 15-second videos that mimic the song-and-dance-infused movies of Bollywood, the country's film industry.

To sustain momentum in India, Bytedance had invested heavily and backed government initiatives to raise TikTok's profile. It had pledged to invest $1 billion in India over the next few years through expansion and construction of a data center. It sponsored "Bala," a Bollywood romantic comedy featuring protagonists who make a lot of TikTok videos.

The investment came after an Indian court blocked TikTok from app stores in April 2019 after ruling that the app could expose children to pornography, sexual predators and cyberbullying. The court later reversed its decision after TikTok appealed.

The ban, which lasted less than two weeks, cost the app more than 15 million downloads in India, according to Sensor Tower. Those losses, combined with a similar ban in Indonesia in 2018 over inappropriate content, spurred Bytedance last year to start tailoring in earnest its content policies to individual markets, according to a person familiar with the matter.

The company was wary of further bans in India, which it views as a huge growth market, the person said. Bytedance also owns other popular apps in India, including the social-media app Helo and a music-streaming app called Resso.

TikTok India's public-policy director, Nitin Saluja, said in an interview last year "there is an enabling environment for any company to have an India-first approach" and that Bytedance wanted to further invest in the country.

India has been a battleground for the Trump administration's effort to get allies to shun Chinese technology, especially cellular equipment from Huawei Technologies, over what the White House says are national-security concerns.

Officials in the U.S. and allied countries have said China's authoritarian government could order Huawei to potentially spy on or disrupt communications, The Wall Street Journal reported last year.

--Stu Woo contributed to this article.

Write to Rajesh Roy at rajesh.roy@wsj.com and Shan Li at shan.li@wsj.com 



  Corrections & Amplifications


  This article was corrected at 2140 GMT to reflect that WeChat is the messaging app from Tencent Holdings Ltd. The original version spelled Tencent incorrectly.