The Organization of Mamorian Nationalists was a human Insurrectionist group. Formed in 2537, it was a splinter group of the Mamorian Underground Army that believed the MUA's policy of trying to attack only United Nations Space Command military targets was not effective, and wanted to instead intimidate the pro-UNSC civilian population and embolden those with rebel loyalties to make it extremely difficult for UNSC forces to operate on Mamore.