Demons, more commonly known by their Sinhala names yakshaya and yaka (Sinhala: යක්ෂයා/යකා), form an important part of Sinhalese folklore in Sri Lanka. They are under the rule of a king, who has forbidden them to kill humans. Therefore they bring down various diseases upon humans, so that they can gain the satisfaction that they are denied because of this ban. Victims who are believed to have been affected by demons then have to be cured and the demons repelled through exorcism rituals.