Friends and family searched for missing hajj pilgrims on Wednesday as the death toll at the annual rituals, which were carried out in scorching heat, surged past 900.
Relatives scoured hospitals and pleaded online for news, fearing the worst after temperatures hit 51.8 degrees Celsius (125 Fahrenheit) in Mecca, Islam's holiest city, on Monday.
About 1.8 million people from all over the world, many old and infirm, took part in the days-long, mostly outdoor pilgrimage, which this year fell during the oven-like Saudi summer.
An Asian diplomat told AFP there were "around 68 dead" from India and that others were missing.
"Some (died) because of natural causes and we had many old-age pilgrims. And some are due to the weather conditions, that's what we assume," he said.
An Arab diplomat told AFP that deaths among Egyptians alone had jumped to "at least 600", from more than 300 a day earlier, mostly from the unforgiving heat.
That figure brought the total reported dead so far to 922, according to an AFP tally of figures released by various countries.
The diplomat later added that Egyptian officials in Saudi Arabia had received "1,400 reports of missing pilgrims", including the 600 dead.
Facebook and other social media networks have been flooded with pictures of the missing and requests for information.
Fatalities have also been confirmed by Jordan, Indonesia, Iran, Senegal, Tunisia and Iraq's autonomous Kurdistan region, though in many cases authorities have not specified the cause.
A second Arab diplomat told AFP on Wednesday that Jordanian officials were looking for 20 missing pilgrims, though 80 others who were initially reported missing were located in hospitals.
Saudi Arabia has not provided information on fatalities, though it reported more than 2,700 cases of "heat exhaustion" on Sunday alone.
Last year more than 200 pilgrims were reported dead, most of them from Indonesia.
(With inputs from AFP)