In the Indian state of Tripura, the counterparts of Mrus are known as Riangs. However, on many occasions, Mrus are contemptuously called Mro-Dang or Myawktong, meaning lower type of animal being. But Mrus introduce themselves as Mro-cha. The word Mru means man and cha stands for being. The two main streams that flow through Saingdin are Re Chaung in the east and Sit Chaung in the west. Both streams originate from the northern part of the region which forms the boundary between Buthidaung Township and the Arakan Hill Tracts. The two streams meander between cliffs for before they finally join near Tharaungchaung village. The two streams flood during the monsoon season and normally subside after the rains. Water transportation is difficult due to large rocks obstructing the streams. Canoes and bamboo rafts are the only means of transportation to the interior area of the region. On the sloping banks of the two streams, the Mru grow tobacco in the alluvial deposits after clearing naturally grown "kaing" grass. They also grow cotton, cane, and bamboo to sell in a weekly bazaar near the waterfall. As of 1931, the Saingdin area consists of 90 hamlets and each hamlet contains between two and twenty bamboo houses. The population, according to the 1931 Census is 3,390, of which 1,779 are males. Currently, about 70,000 Mru live on the border of Myanmar with India and Bangladesh. The majority of Mru people, approximately 12,000, live in Myanmar within the Yoma District and the Arakan Mountains in western Myanmar. These figures are, however, just rough estimates as the last census was conducted in 1931 when the country was under the colonial rule. At that time, the total number of Mru people was estimated around 13,766. Around 200 more villages making up of between 20,000 and 25,000 people are located in the Chittaung Hills of southern Bangladesh. Another 2,000 Mrus inhabit the districts of West Bengal, India. It is estimated that the population will grow to 85,700 by 2020. The Mru people primary speak the Mru language, a Mruic language of the Tibeto-Burman group of the Sino-Tibetan family. Dialects of Mru include Anok, Downpreng and Sungma. The language is considered "Severely endangered" by UNESCO.