Nearly 2 million Muslims from around the world have begun the yearly hajj pilgrimage in Saudi Arabia at Mecca, Islam's holiest site.
The faithful started the annual five-day ritual Sunday with walking counterclockwise around the Kaaba, the cube-shaped structure at the center of the Grand Mosque of Mecca, which Muslims believe is the spot where the Prophet Abraham built his first temple.
Observant Muslims around the world face toward the Kaaba during their five daily prayers.
During the hajj, devoted Muslims perform a series of religious rituals. In addition to walking around the Kaaba, they also drink the alkaline water from the Well of Zamzam, believed to have healing qualities. They also perform a symbolic stoning of the devil.
The pilgrimage is one of the five pillars of Islam and all able-bodied Muslims who can afford to do so are expected to take part in the hajj at least once in their lifetimes.
Saudi Arabia's Ministry of Hajj and Umrah has urged pilgrims to think of their safety in hopes of preventing stampedes that in previous years have led to deaths. During the 2015 hajj, a stampede among pilgrims in the city of Mina, where some of the deadliest incidents have occurred, killed at least 2,426 people, according to the Associated Press.
The ministry on Sunday urged "brother and sister pilgrims" to pay attention to scheduling of rituals to avoid the dangers of overcrowding.