Masumiyeh DistrictMasumiyeh District is in Arak County, Markazi province, Iran. Its capital is the city of Karchan.HistoryAfter the 2006 National Census, Masumiyeh and Moshkabad Rural Districts were separated from the Central District in the formation of Masumiyeh District.DemographicsPopulationAt the time of the 2011 census, the district's population was 16,373 people in 5,115 households. The 2016 census measured the population of the district as 15,889 inhabitants in 5,207 households.