Arroyo gives reasons for martial law declaration in 20-page letter . Maguindanao is part of an autonomous region in predominantly Muslim Mindanao , which was set up in the 1990s to quell armed uprisings by people seeking an independent Muslim homeland in the predominantly Christian Asian nation . Report : However , Senate might jointly convene sooner , House Speaker says . At least six members of Ampatuan family arrested , ABS - CBN reports . Authorities seized at least one house and ranch belonging to family .
Arroyo gives reasons for martial law declaration in 20-page letter . Report : However , Senate might jointly convene sooner , House Speaker says . At least six members of Ampatuan family arrested , ABS - CBN reports . Authorities seized at least one house and ranch belonging to family .