Every year, the Saudi Arabian government's Ministry of Hajj sets up a tent city to support Muslim pilgrims in the village of Mina, where the ritual Stoning of the Devil takes place as part of the overall Hajj pilgrimage to Mecca. A tent city is also established annually at Mount Arafat, another essential stop during the Hajj. Because up to four million pilgrims may be performing the Hajj annually, the tent cities are densely inhabited with 20-40 people per tent. As such, fire and disease outbreaks are constant concerns. Since the late 1990s, Saudi authorities have started using fireproof tents to reduce the risks of a major fire.