Hundreds of thousands of Muslims have flocked to the Saudi holy city of Makkah for the Hajj pilgrimage unfolding this year in the shadow of the Gaza siege by Israeli forces.
One of the world's largest annual religious gatherings officially begins on Friday, and Saudi officials are trying to keep the focus on prayers.
The Gulf kingdom's minister in charge of religious pilgrimages, Tawfiq al-Rabiah, warned last week that "no political activity" will be tolerated.
The Hajj, one of the five pillars of Islam, must be performed at least once by all Muslims with the means, and as of Thursday around 1.2 million pilgrims had already arrived in Saudi Arabia from abroad to take part.
Last year saw more than 1.8 million people complete the Hajj rites which last for several days. Around 90 percent came from overseas, mainly from elsewhere in the Arab world and from Asia, according to official figures.
Israel's military operations against Hamas fighters in Gaza have "created a lot of anger in (the) broader Muslim world", turning this year's Hajj into a "test" for Saudi leaders, said Umer Karim, an expert on Saudi politics at the University of Birmingham.
"Protest or performance is bound to happen by individuals or groups of pilgrims, and Saudis understand this is a slippery slope," he said. "Thus for Saudi rulers conducting Hajj is a matter of prestige but also a test of their governance."
- Pilgrimage politics -
The Israeli army had launched a devastating offensive on the Gaza Strip that has left at least 37,164 dead, the majority of them civilians, according to data from the health ministry of the Hamas-led Gaza government.
Saudi Arabia has never recognised Israel but de facto ruler Crown Prince Mohammed bin Salman was considering establishing formal diplomatic ties with Israel before the October 7 attack.
Saudi leaders remain in talks with US officials about a so-called mega-deal that would see Riyadh recognise Israel in exchange for a deeper security relationship with Washington.
However Saudi officials have said ties with Israel are impossible without "irrevocable" steps towards recognition of a Palestinian state, which Israel has long opposed.
Saudi King Salman issued a decree on Monday to host 1,000 pilgrims "from the families of martyrs and the wounded from the Gaza Strip", bringing to 2,000 the number of Palestinian pilgrims to be hosted this year, according to the official Saudi Press Agency.
The Hajj is a source of legitimacy for Saudi rulers, and King Salman's title includes "Custodian of the Two Holy Mosques" in Makkah and Madinah.
Yet the Saudi government also "uses the pilgrimage to control Muslims worldwide", as it can potentially bar critics from performing an essential religious rite, said Madawi al-Rasheed, a Saudi academic and opposition figure based in London.
"The Saudis will increase their control over the pilgrims to prevent any mobilisation around support for Gaza. It remains to be seen whether the pilgrims will respect Saudi wishes."
- Heat fears -
The rites in Makkah and its surroundings fall again this year during the hot Saudi summer, with officials forecasting average high temperatures of 44 degrees Celsius (111 degrees Fahrenheit).
Last year more than 2,000 people suffered heat stress, which includes heatstroke, exhaustion, cramps and rashes, according to Saudi authorities.
The real figure was probably far higher, as many sufferers were not admitted to hospitals or clinics.
Worshippers have already arrived en masse in Makkah to begin circling the Holy Kaaba, the large black cubic structure in the Grand Mosque in Makkah towards which all Muslims pray.
Large crowds at the Hajj have proved hazardous in the past, most recently in 2015 when a stampede during the "stoning the devil" ritual in Mina, near Makkah, killed up to 2,300 people in the deadliest Hajj disaster.
Managing the gathering represents "a logistical achievement", said Bernard Haykel, a Saudi expert at Princeton University, with extensive surveillance and monitoring in place for security and health reasons.
Pilgrimages to Makkah are a financial windfall for Saudi Arabia, generating billions of dollars as the world's biggest crude oil exporter tries to develop its tourism sector.
Umrah, the pilgrimage which can be performed throughout the year, drew 13.5 million worshippers last year, and authorities are targeting 30 million Hajj and Umrah pilgrims by 2030.