At least 14 Jordanian pilgrims have died due to “extreme heat” during the Hajj pilgrimage in Saudi Arabia.

Jordan’s foreign ministry said on Sunday that “14 Jordanian pilgrims died during the Hajj pilgrimage, and 17 others are missing.” The ministry said its citizens died “after suffering strokes caused by extreme heat,” news agency AFP reported.

The ministry said it was coordinating with Saudi authorities to bury the dead in Saudi Arabia or transfer them to Jordan.

Iran also reported that a total of five Iranian pilgrims died during the Hajj pilgrimage; however, they did not reveal the reason behind their deaths.

Saudi Arabia has not yet released any official statement about the deaths. However, Saudi Health Ministry spokesman Mohammed al-Abdulali told reporters that more than 2,760 pilgrims suffered from heat and sunstroke on Sunday.

He also said the numbers are expected to rise and urged pilgrims to avoid stepping out during peak hours (between 11 a.m. and 3 p.m.) and stay hydrated. “Heat stress is the biggest challenge,” he was quoted as saying by the Associated Press.

According to news agency Reuters, temperatures in Mecca are expected to reach 47 degrees Celsius on Monday.

The hajj pilgrimage ends on Wednesday. It is one of the largest mass gatherings worldwide, with more than 1.8 million pilgrims expected to attend this year, according to the Saudi General Authority for Statistics.

At least 240 people died during the Hajj last year, many of them from Indonesia. Various countries gave figures but did not disclose the causes of death. More than 2,000 people suffered from heat stress during the Hajj.

A Saudi official told AFP this week that more than 10,000 heat-related illnesses were recorded last year, 10 percent of which were heatstroke.