Millions of people across India are twisting themselves into complex yoga positions as the country celebrates International Yoga Day.

Prime Minister Narendra Modi joined a crowd of 30,000 schoolchildren and other residents of the northern city of Chandigarh for a mass yoga session Tuesday.

Before beginning the exercises, Modi urged people to make yoga a part of their lives, saying the practice — which began in ancient India — doesn't differentiate between the rich and poor, and is accessible to all.

Similar yoga events were being held in villages, towns and cities all over India. Last year, the United Nations proclaimed June 21 as International Yoga Day.

Many believe that practicing yoga is the best way to calm the mind and the best form of exercise for the body.