More than two million Muslims began the main rituals of the annual hajj pilgrimage on Wednesday, heading from Mecca to Mina where they rest and pray for the night before moving on to Mount Arafat.
The pilgrims, of whom nearly 1.7 million came to Saudi Arabia from abroad, started to travel by bus, on foot or with the Mashair light railway to the arid plain of Mina where they will spend the night in government supplied tents.
The pilgrims' stay in Mecca has so far been incident-free, with some 25,700 members of the Saudi security forces deployed throughout the kingdom's holy cities.
In Mina, 100 civil defence teams are on call, ready to deal with emergencies.
The passage to Mina marks the official launch of the hajj on the eighth day of the Muslim calendar month of Dhul Hijja.
The day is known as Tarwiah (Watering) as pilgrims in the past stopped at Mina to feed their animals and stock up for the following day's trip to Mount Arafat.
On Thursday, they will ascend to Mount Arafat, some 10 kilometres (six miles) southeast of Mina, to spend the day in prayer.
After sunset, they head to Muzdalifah, between Mina and Arafat, where pilgrims collect stones to throw at the devil, one of the last rituals which takes place Friday and marks the first day of Eid al-Adha, the annual feast of sacrifice.
The symbolic "stoning of the devil" is followed by the ritual sacrifice of an animal, usually a lamb.
During the remaining three days of the hajj, the pilgrims continue the ritual stoning before performing the circumambulation of the Kaaba shrine in Mecca and heading home.