India’s prime minister Narendra Modi performed dawn exercises with as many as 50,000 people on Thursday as he led celebrations to mark the fourth International Day of Yoga.

The Hindu nationalist leader has incorporated yoga into his personal brand, each year leading the flagship display of a world event that was recognised by the UN at his request.

Estimated to have originated in India some 5,000 years ago, yoga has ballooned into a £60bn lifestyle industry with teachers, followers and commercial enterprises linked to the discipline around the world.

And while the spiritual practice is not seen as being tied to any single religion, critics say Mr Modi has utilised yoga in promoting his vision of India as a predominantly Hindu nation.

This year, Mr Modi led exercises in the town of Dehradun in the foothills of the Himalayas. He urged Indians to be proud of their culture and history.

“The gems of India’s unique heritage, such as yoga, will be respected by the world at large only when we ourselves respect our culture and traditions,” he said.

Around the world, public yoga events were held in Afghanistan, Japan and Peru, while Australia and South Africa celebrated on Monday.

“From Tokyo to Toronto, from Stockholm to Sao Paulo, yoga has become a positive influence in the lives of millions,” Mr Modi told participants on the lush green lawns.

“In a world where non-communicable diseases, stress and lifestyle related ailments are rising, yoga can play a central role in mitigating these diseases to create a healthy mind and body.”

In the buildup to Thursday’s event, Mr Modi took part in a social media campaign, begun by his BJP party ministers, to get people to share videos of their fitness workouts on Twitter.

Celebrities from Bollywood actors to sports superstars got involved, and Mr Modi’s own video showed him performing yoga on a boulder in his prime ministerial gardens.

Social media was again awash with videos emulating Mr Modi’s on Thursday, including those from staff at Delhi airport, pupils at thousands of schools and members of India’s armed forces.

The Indian navy released pictures of sailors doing yoga on board the world’s oldest aircraft carrier, the INS Viraat, decommissioned last year, and soldiers guarding the world’s highest battleground, the Siachen glacier in northern Jammu and Kashmir state, did yoga routines at an altitude of around 18,000 feet.

The events clearly mustered a huge amount of public support. For some, however, there was a sinister edge to having public institutions take part in a scheme closely associated with the prime minister’s messaging. Even prisons were involved, with 15,000 inmates due to take part in yoga events on Thursday in the capital alone.

Sagarika Ghose, a prominent journalist and political commentator, wrote on Twitter: “Believer in yoga, try every morning, immense benefits. But concerned: why does a GOVERNMENT need to promote yoga? Yoga’s an individual choice, a personal option.”

Mr Modi’s rule, she said, was “fast becoming an escapist Bollywood film where song and dance attempt to distract from hard realities”. One of the most liked responses to Ms Ghose’s tweet told her to “go to Pakistan” if she couldn’t show loyalty to India.

For Ajay Mehra, a political scientist at Delhi University, the International Day of Yoga “has become an imposition”, forced on the people by government.

“Something like yoga should not be part of a political project,” he told The Independent, adding that there were certain yogic practices – chanting mantras for instance – that could be offensive to some groups in a plural society, “Muslims in particular”.