Afghans in Iran are mostly refugees who have fled wars in Afghanistan since the April 1978 Saur Revolution in Kabul. It also includes an unknown number of illegal migrant workers as well as a smaller number of traders, students, diplomats, tourists and other visitors. According to the United Nations High Commissioner for Refugees (UNHCR), there are 950,000 registered Afghan citizens living in Iran. However, Iran's Ministry of Interior estimates that the total number of Afghans in Iran is around 3 million. The ones designated refugees are under the care of the UNHCR, and provided legal status by the Government of Iran. They cannot obtain Iranian citizenship or permanent residency, and live in Iran under time-limited condition of stay.