A Tibetan man stirs butter tea made for the arriving guest during the function organised to mark Losar or the Tibetan New Year at a Tibetan Refugee Camp in Lalitpur February 19, 2015. Tibetans across the world marked the arrival of the New Year with prayers and festivities. (Photo by Niranjan Shrestha/AP Photo)

Pedestrians cover their face as they walk along the dusty road in Kathmandu, Nepal February 27, 2017. Nepal has forced 2,500 old vehicles off roads in its capital city of Kathmandu, part of a fight against alarming air pollution levels that have hit nine times World Health Organisation (WHO) limits. Air pollution has been a chronic problem in rapidly growing Kathmandu, which sits in a Himalayan valley and is home to more than 3mn people. (Photo by Navesh Chitrakar/Reuters)

A Nepalese devotee bows in front of a cow during the 'Gai Puja', also known as the Cow Worship Day, as part of the Tihar festival in Kathmandu, Nepal, 11 November 2015. The Tihar festival is the second most important event for Nepalese Hindus. During the celebrations people worship cows, considered the incarnation of Lord Laxmi, the god of wealth. (Photo by Narendra Shrestha/EPA)

A Hindu Sadhu smokes marijuana from a chillum inside the Pashupatinath Temple premise in Kathmandu, Nepal on March 6, 2016. Holy men from India and Nepal come to celebrate the festival of Maha Shivaratri by smoking, smearing their bodies with ash, offering prayers devoted to the Hindu Deity, Lord Shiva. (Photo by Skanda Gautam via ZUMA Wire)

A Nepalese Hindu devotee dresses as a deity as he prepares to participate in festivities at the Shikali Temple during celebrations for the Shikali Jatra festival in the village of Khokana, on the outskirts of Kathmandu, on October 19, 2015. Local villagers, who normally do not celebrate the country's most famous festival of Dashain, celebrate the Shikali Jatra each year. (Photo by Prakash Mathema/AFP Photo)

Buddhist monks take shelter under a tarpaulin sheet to protect themselves from the rain as they attend the birthday celebrations of the Tibetan spiritual leader the Dalai Lama (unseen) at Drepung Loseling Monastery in Mundgod, in the southern state of Karnataka, India, July 6, 2016. (Photo by Abhishek N. Chinnappa/Reuters)

A Nepalese Hindu devotee takes a holy bath as they mark the Mother's Day Festival at Matathirtha on the outskirts of Kathmandu on May 6, 2016. Nepalese Hindu devotees come from across the country to bathe, offer prayers and leave offerings at the Matathirtha Temple during the event, which honours mothers who have passed away. (Photo by Prakash Mathema/AFP Photo)

Nepalese Hindu devotees offer oil lamps in the Bagmati River as they observe the festival of Bala Chaturdashi in the early morning hours at the Pashupati Temple in Kathmandu, Nepal, 28 November 2016. Seven kinds of seeds – paddy, barley, sesame, wheat, gram, maize and finger millet – are sown around the temple premises in the name of loved ones departed during the last three years, in the belief that the departed souls will receive salvation. (Photo by Narendra Shrestha)