Two million Muslims gathered at Saudi Arabia's Mount Arafat on Saturday to participate in the world's largest annual gathering of the community
Pilgrims clad in white robes signifying a state of purity spent the night in a sprawling encampment around the hill where Islam holds that God tested Abraham's faith by commanding him to sacrifice his son Ismail. It is also where Prophet Mohammad gave his last sermon.
Other worshippers who had been praying in the nearby Mina area ascended on buses or on foot from before dawn. Some carried food, carpets for camping and fans to keep cool as temperatures rose towards 40 degrees Celsius (104 degrees Fahrenheit).
Saudi Arabia has said more than two million pilgrims, mostly from abroad, have arrived for the five-day ritual, a religious duty once in a lifetime for every able-bodied Muslim who can afford the journey.
Among them are 200 survivors and relatives of victims of the attacks on two New Zealand mosques in March.
The pilgrims will spend the day on Mount Arafat. By sunset, they will move to the rocky plain of Muzdalifa to gather pebbles to throw at stone columns symbolising the devil at Jamarat on Sunday, which marks the first day of Eid al-Adha, or the feast of sacrifice.
Saudi Arabia stakes its reputation on its guardianship of Islam's holiest sites, Mecca and Medina, and organising the pilgrimage.
A perennial concern is a potential for disease spreading among pilgrims, who spend five days in close quarters, often eating outside and sleeping on the ground near holy sites.
The world's largest annual gathering of Muslims has in the past also seen stampedes, fires, and riots, with authorities sometimes struggling to respond. Hundreds were killed in a crush in 2015, the worst disaster to strike hajj for at least 25 years.
Pilgrimage is also the backbone of a Saudi plan to expand tourism under a drive to diversify the kingdom's economy away from oil. The hajj and year-round umrah generate billions of dollars in revenue from worshippers' lodging, transport, fees, and gifts.
Officials aim to increase the number of umrah and hajj pilgrims to 15 million and 5 million respectively by 2020 and the umrah number to 30 million by 2030.