Some 2 million Muslims from around the world are starting the annual hajj pilgrimage in Saudi Arabia.
The pilgrims, clad in seamless cloth, will perform a series of rituals over five days that include walking counterclockwise seven times around the Kaaba, Islam's holiest shrine, at Mecca's Grand Mosque.
They will also visit the plains of Arafat to hold vigil and seek divine mercy and throw pebbles in a ritual known as the Stoning of the Devil.
The hajj is one of the five pillars of Islam that every capable Muslim must perform at least once in their life.
Around 90,000 Iranians were expected to attend the pilgrimage this year after boycotting the event following a 2015 stampede that killed more than 2,000 people.
This year’s hajj also comes amid a diplomatic crisis between Qatar and other Arab countries, including Saudi Arabia, and after the extremist group Islamic State lost swathes of territory it once controlled in Iraq and Syria.