The Khasi dao is a form of two-handed sword used by the Khasi people inhabiting the hills to the south of the Brahmaputra valley. Although a well balanced two-handed sword, their principal role is in religious ceremonies related to the agricultural cycle.
Its distribution is not just confined to the Khasi hills. Variants of it form part of the religious practices of the Ao and Lhota Nagas and the Bodo people. Among the Ao where they are referred to as noklang, three times a year a mithun (a forest-dwelling relative of the water buffalo) is sacrificed to ensure the goodwill of the gods and safeguard the rice harvest. During the ritual, a pair of noklang are placed upright in the ground by their tangs. If one of the noklang falls over during the ceremony, it is considered a bad omen for the harvest.