From the world's highest battle field to Delhi's Rajpath, India in a first of its kind event, observed the International Yoga Day celebrations along with some 191 countries across the world.

Prime Minister Narendra Modi led tens of thousands of people in a yoga session in the centre of the capital on Sunday to showcase the country's signature cultural export, which has prompted criticism of fomenting social divisions at home.The ancient Hindu discipline which has become an estimated $27 billion industry in the United States is being celebrated across the world as an International Yoga Day which Modi pushed for soon after taking power last year.

Rajpath turns into Yogapath, Modi in various asanas

Rajpath in New Delhi gets a make-over ahead of the International Yoga Day | Source: PTI

Prime Minister Narendra Modi performs yoga with others to mark the International Day of Yoga, in New Delhi | Source: Reuters

PM Modi leads a record gathering of some 40,000 people as part of International Yoga Day celebrations | Source: Reuters

Source: PTI

Source: PTI

Source: PTI

Delhi CM, Lt Governor also reach Yogapath

Delhi CM Arvind Kejriwal at a mass yoga session along with other yoga practitioners at Rajpath | Source: PTI

Children take selfie with Delhi Lt Governor Najeeb Jung at a mass yoga session to mark the International Day at Rajpath | Source: PTI

Red Fort

Brahmkumaris at a Yoga Session on the eve of International Yoga Day near Red Fort in New Delhi | Source: PTI

Varanasi - the spiritual capital of India

People performing Jal Yoga in Varanasi | Source: PTI

Gujarat Chief Minister takes the lead

Gujarat Chief Minister Anandiben Patel practicing Yoga on the eve of International Yoga Day in Gandhinagar | Source: PTI

Sushma Swaraj reaches US to inaugurate Yoga day

External Affairs Minister Sushma Swaraj with Ambassador Asoke Mukerji (right), India's Permanent Representative to the United Nations, arrives to attend the International Day of Yoga event at the UN in New York | Source: PTI

At the world's highest battle field, Siachen.

Army personnel at a Yoga Session on the eve of International Yoga Day at Siachen Glacier. | Source: PTI

Across foundations and schools

Yoga enthusiasts perform Yoga at the inauguration of the International Yoga day organised by Isha Foundation in Bengaluru | Source: PTI

Students perform Yoga on the eve of International Yoga Day at Sanathnagar in Hyderabad | Source: PTI

Muslim children performing Yoga in a Madrasah in Surat on Sunday | Source: PTI

Meanwhile, Yellow Butterfly Yoga, a yoga training organisation also observed Yoga Day celebrations with full enthusiasm in New Delhi.

People chanting 'om' during the session | Source: ScoopWhoop/Sneha Mitra

Yoga artists perform Head Stand to observe the Yoga day in New Delhi | Source: ScoopWhoop/Sneha Mitra

Women perform yoga in the national capital.| Source: ScoopWhoop/Sneha Mitra

Participants performing 'Tadasana' during the International Yoga Day celebrations. | Source: ScoopWhoop/Sneha Mitra

International Yoga Day is also being celebrated in various other parts of the world. In Britain, mats will be rolled out along the banks of the River Thames.