Some 2 million Muslims from around the world are gathering at Mount Arafat near the Saudi holy city of Mecca to mark the peak of the annual hajj pilgrimage.
The pilgrims gathered at the stone hill surrounded by desert on August 31 -- the second day of the hajj -- to hold a vigil and seek divine mercy.
This is the site where the Prophet Muhammad is believed to have delivered his last sermon some 1,400 years ago.
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.
Iran alone reported 464 deaths and subsequently accused the Saudi authorities of being "at fault" for them -- a charge Saudi officials rejected.
Saudi authorities said more than 100,000 security personnel were deployed around Mecca and Medina to protect and marshal pilgrims, along with thousands of cameras.
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 swaths of territory it once controlled in Iraq and Syria.