Muslim pilgrims pray on Mount Arafat in hajj climax amid Israel's war on Gaza

More than 1.5 million Muslims braved extreme heat to reach Mount Arafat on Saturday for the high point of the annual hajj pilgrimage, praying for hours, especially for Palestinians in war-ravaged Gaza.

Clad in white, worshippers began arriving at dawn for the most gruelling day of the annual rites, ascending the rocky, 70-metre (230-foot) hill where the Prophet Mohammed is believed to have given his last sermon.

"This is the most important day," said 46-year-old Egyptian Mohammed Asser, who came prepared with a list of prayers. "I pray also for the Palestinians. May God help them."

This year's hajj is unfolding in the shadow of Israel's war on Gaza, which has killed 37,266 people in in the enclave, mostly civilians.

Saudi Arabia's minister in charge of religious pilgrimages, Tawfiq al-Rabiah, warned last week that "no political activity" would be tolerated during the hajj.

But that did not stop at least one pilgrim from chanting in support of the Palestinians who have endured more than eight months of incessant bombardment.

"Pray for our brothers in Palestine, in Gaza... may God give victory to the Muslims," he shouted.

In a message to hajj pilgrims on Saturday, Iranian supreme leader Ayatollah Ali Khamenei said "the ironclad resistance of Palestine and the patient, oppressed people of Gaza... must be fully supported in every way".

Some 2,000 Palestinians are performing the hajj at the special invitation of Saudi King Salman, official media said.