MAKKAH: Pilgrims perform the last major ritual of the haj, the “stoning of the devil”, in western Saudi Arabia on Sunday, as Muslims in parts of the world celebrate Eidul Azha.

Beginning at dawn, the 1.8 million Muslims undertaking the pilgrimage this year will throw seven stones at each of three concrete walls symbolising the devil in the Mina valley, located outside Makkah, the holiest city in Islam.

The ritual commemorates Prophet Ibrahim’s stoning of the devil at the three spots where it is said Satan tried to dissuade him from obeying God’s order to sacrifice his son.

The stoning ritual has been witness to multiple stampedes over the years, most recently in 2015 when up to 2,300 worshippers were killed in the worst haj disaster.

The site has been revamped since then to streamline the movement of the large crowds.

On Saturday night, pilgrims collected stones and slept under the stars in the plain of Muzdalifah, located halfway between Mina and Arafat, where they had spent the day praying outside in heat that reached 46 degrees Celsius (114.8 degrees Fahrenheit).

Worshippers have tried to take the gruelling conditions in stride, seizing what for many is a once-in-a-lifetime chance to pray at Islam’s holiest shrines.

One of the five pillars of Islam, the haj must be performed at least once by all Muslims with the means. This year’s figure of 1.8m pilgrims is similar to last year’s, and Saudi authorities said on Saturday that 1.6m of them came from abroad.

The stoning ritual coincides with the feast of the sacrifice, or Eidul Azha, which honours Prophet Ibrahim’s willingness to sacrifice his son before God offered a sheep instead.

Worshippers typically slaughter a sheep and offer part of the meat to the needy.