NEW DELHI (AFP) - India on Monday (June 29) banned 59 Chinese mobile apps, including the wildly popular TikTok and WeChat, over national security and privacy concerns just weeks after a deadly Himalayan border clash between the nuclear-armed neighbours.

Relations between the world's two most populous nations have been strained following the deaths of 20 Indian troops in hand-to-hand fighting with their Chinese counterparts on the western end of the high-altitude, contested border in mid-June.

The apps "are engaged in activities... prejudicial to sovereignty and integrity of India, defence of India, security of state and public order," the ministry of information technology said in a statement.

"The government of India has decided to disallow the usage of certain apps... This decision is a targeted move to ensure safety and sovereignty of Indian cyberspace."

The statement said the move was taken after several complaints were received by the ministry alleging theft of users' data and violations of user privacy.

It was unclear when the ban would come into force.

The Indian soldiers were killed in a brawl along the disputed border in northern Ladakh region on June 15 in the deadliest faceoff for almost half a century between the two countries. They had fought a war over the border in 1962.

New Delhi has accused China of intruding into its territory in the region, a charge Beijing has denied.

Thousands of soldiers remain on alert, although both sides said they were trying to resolve the standoff through dialogue.

The deaths triggered massive outrage and street protests in India. There have been calls for the banning of Chinese businesses, which export goods worth nearly US$60 billion to India.

Chinese mobiles have an almost 65 per cent share in the local smartphone market, while video-sharing apps like TikTok and Helo are popular among India's youths.

There are estimated to be about 120 million TikTok users in India, making the South Asian nation of 1.3 billion people the app's biggest international market.

Other apps on the banned list include microblogging app Weibo and strategy game Clash of Kings.

The June 15 violence took place around 4,500 metres above sea level in the Galwan river valley.

It was the first time troops have been killed on their frontier since 1975 There is an understanding between the nuclear-armed neighbours that their troops in the inhospitable region will not use firearms.