At least 863 pilgrims were injured in the crush, said the Saudi civil defense directorate, which provided the death toll. The tragedy struck as Muslims around the world marked the start of the Eid al-Adha holiday, AP reported.
It was the second major disaster during this year's Hajj season, raising questions about the adequacy of measures put in place by Saudi authorities to ensure the safety of the roughly 2 million Muslims taking part in the pilgrimage.
A crane collapse in Mecca nearly two weeks earlier left 111 people dead.
Many of the victims were crushed and trampled to death as they were on their way to perform a symbolic stoning of the devil by throwing pebbles against three stone columns in Mina, a large valley about 5 kilometers (3 miles) from Mecca that has been the site of Hajj stampedes in past years. The area houses more than 160,000 tents where pilgrims spend the night during the pilgrimage.
Two survivors interviewed by The Associated Press said the disaster began when one wave of pilgrims found themselves heading into a mass of people going in another direction.
"I saw someone trip over someone in a wheelchair and several people tripping over him. People were climbing over one another just to breathe," said one of the survivors, Abdullah Lotfy, 44, from Egypt. "It was like a wave. You go forward and suddenly you go back."
Lotfy said that having two flows of pilgrims interacting in this way should never have happened. "There was no preparation. What happened was more than they were ready for," he said of the Saudi authorities.
The kingdom's Interior Ministry said later Thursday that the crush appears to have been caused by two waves of pilgrims meeting at an intersection. King Salman ordered the creation of committee to investigate the incident.
The ministry's spokesman, Maj. Gen. Mansour al-Turki, said high temperatures and the fatigue of the pilgrims may also have been factors in the disaster. He said there was no indication that authorities were to blame for the event, adding that "unfortunately, these incidents happen in a moment."
The death toll from Thursday's crush far exceeded that of a similar incident in 2006, near the same site, when more than 360 pilgrims were killed in a stampede. Another stampede at Mina in 2004 left 244 pilgrims dead and hundreds injured.
The deadliest Hajj-related tragedy happened in 1990, when at least 1,426 pilgrims perished in a stampede in an overcrowded pedestrian tunnel leading to holy sites in Mecca.
The latest tragedy is certain to have touched many different countries as the victims likely included pilgrims of different nationalities.
More than 100 Iranian pilgrims perished. The chief of the Iranian Hajj organizing agency, Saeed Ohadi, said that "mismanagement by the Saudis" led to the tragedy. Deputy Foreign Minister, Hossesin Amir-Abdollahian, told the official IRNA news agency that his ministry summoned the Saudi envoy to Tehran for an official protest over what he called the "inadequate performance of Saudi authorities" in the incident.