AMMAN: At least 19 Jordanian and Iranian pilgrims have died while on the Hajj pilgrimage in Saudi Arabia, authorities from their countries said on Sunday, as temperatures soar in the kingdom.

“14 Jordanian pilgrims died and 17 others were missing” during the performance of Hajj rituals, Jordan’s foreign ministry said in a statement, not specifying their cause of death.

Iranian Red Crescent chief Pirhossein Koolivand said “five Iranian pilgrims have lost their lives so far in Mecca and Medina during the Hajj this year”, also not saying how they died.

Muslim pilgrims pray on Mount Arafat in Hajj climax

The Hajj, one of the world’s biggest religious gatherings, is one of the five pillars of Islam and all Muslims with the means must perform it at least once.

Temperatures have pushed well past 40 degrees Celsius (104 degrees Fahrenheit) during the annual pilgrimage that around 1.8 million Muslims are taking part in this year.

Many of the rituals are performed outdoors and on foot, creating challenges especially among the elderly. Saudi Arabia has not provided any information on fatalities.

But the kingdom has implemented heat mitigation measures, including climate-controlled areas, distributes water, and offers advice to pilgrims on protecting themselves from the sun.

Saudi warns of above-average heat during the Hajj

During last year’s Hajj at least 240 people — many from Indonesia — died, according to figures announced by various countries which also did not specify causes of death.

More than 10,000 heat-related illnesses were recorded last year, 10 percent of them heat stroke, a Saudi official told AFP this week. A Saudi study said regional temperatures were rising 0.4 C each decade, and worsening heat may be outpacing mitigation measures.