At least 90 Indian nationals have died during this year's Hajj pilgrimage, largely due to an intense heatwave, according to sources cited by India Today on Thursday.

In total, 645 deaths have been reported so far, as per a tally from the news agency AFP. The majority of these deaths have been attributed to the extreme heat.

"No accidents have been reported," stated one source.

Previously, an Arab diplomat, speaking on the condition of anonymity, confirmed to AFP that at least 68 Indian nationals had died during the pilgrimage. "Some deaths are due to natural causes, particularly among elderly pilgrims, while others are likely related to the severe weather conditions," the diplomat noted.

There are also reports of several Indians missing.

Earlier this week, Arab diplomats indicated that at least 550 pilgrims had died this year, most due to the extreme temperatures in Mecca, according to AFP.

This year’s pilgrimage saw participation from around 1.8 million people worldwide.

The Hajj pilgrimage, one of the five pillars of Islam, requires all Muslims who are able to undertake it at least once in their lifetime.

This year's Hajj has been notably impacted by a severe heatwave, with temperatures exceeding 50 degrees Celsius, the highest in recent decades. A Saudi study has shown that temperatures in the pilgrimage area have increased by 0.4 degrees Celsius per decade. In 2023, more than 200 pilgrims died during Hajj, with over 2,000 suffering from heat-related stress as temperatures reached 48 degrees Celsius.