The Thai call them "Pi Tong Luang" or The Spirit of the yellow leaves. The are known also by the names "Yumbri" and "Ma Ku". There are about 100 only of them. Most of them are in Nan Province and some in Phrae. It is said that there are still some Mlabri in Kengtung in Burma. They live in nomadic way in small groups up to 10-12. They are probably related to the Mon-Khmer people and may be the a..