Dawn breaks over pilgrims' tents in Mina, outside Mecca, on the third day of the Hajj pilgrimage.
Pilgrims make their way towards pillars in Mina. Stewards are on hand to keep order on historically the most dangerous day of the pilgrimage due to the crowds and stampedes.
Women pilgrims - who normally remove face coverings for the ceremony - join in.
The pilgrims throw stones at pillars where Satan is said to have tempted the Prophet Abraham. The action is a refutation of the temptations of the Devil.
Since the last Hajj, the pillars have been replaced with wide walls allowing more pilgrims to participate and to protect others on the other side.
Saudi authorities have spent millions of dollars improving safety measures at the pilgrimage, which attracts over two million faithful. Digital screens provide instructions in Arabic, left, English and other languages.
After throwing stones, pilgrims pray...
... and shave their heads, or cut some hair off. They then walk back to Mecca, where many repeat the Tawaf - walking around the Kaaba building seven times.
About 10,000 security forces are on patrol and as yet no accidents or stampedes have been reported - unlike last year, when 251 pilgrims were trampled to death.
Muslims in other parts of the world also celebrate the holiday of Eid al-Adha. Here, a prayer service at a mosque near Banda Aceh, an Indonesian city crushed by December's tsunami.