Around two million white-robed pilgrims flooded Mount Arafat and its surrounding plain on Monday as the Hajj, the world's largest annual pilgrimage, converged on the site of the Prophet Mohammed's last sermon.
Chanting the Talbiyah, "O God, here we come, answering your call," pilgrims set off before dawn in a bid to reach the top of Mount Arafat, a hill dominating the plain of Arafat.
Those who did manage to jostle their way through the heaving crowds to the top of the hill, which is also known as Jabal al-Rahma, or the Mount of Mercy, sat on the rocky edges reciting Koranic verses and praying.
Some used their mobile phones to take pictures. Others lay down on straw mats spread over the rocks.
"My feeling cannot be described," said Syrian pilgrim Mossaad Mheymeed standing at the top of Mount Arafat. "I feel it is already judgment day."
"Thank God for this grace," said his companion, Hussein al-Alawi, 55, also from Syria.
The granite hill, rising some 60 metres (yards) from the plain and no more than 200 metres (218 yards) in length and of similar width, is topped with a four-metre pillar, said to represent the spot where the Prophet Mohammed delivered his final Hajj sermon.
Pilgrims vied to touch the white cement structure, some crying, although the pillar, which has turned dark at its lower part through human contact, is not meant to have a religious significance.
Down below, movement on the plain came to a virtual standstill due to the sheer size of the crowd.
Buses stood in four lanes as they fought for use of the road with pedestrians, who crammed the thin spaces between the idling vehicles in a bid to keep moving.
The edges of Arafat plain were marked by women in wheelchairs and children in strollers trying to escape being run over by jostling pilgrims heading in all directions.
The gathering in the plain of Arafat symbolises the climax of the Hajj pilgrimage, which began Sunday with more than two million pilgrims flowing from the neighbouring Muslim holy city of Mecca, or directly into Mina -- a tent city that comes to life only during the five-day annual pilgrimage.
There were no immediate reports of major incidents as security officials focused on crowd control.
Saudi Interior Minister Prince Nayef bin Abdul Aziz said on Wednesday that he could not rule out the possibility of a sabotage attempt by Al-Qaeda during the Hajj pilgrimage.
But Al-Qaeda in the Arabian Peninsula (AQAP) said on Sunday it was against targeting the Hajj.