More than 1.8 million people have arrived in Saudi Arabia from around the globe for the annual Hajj pilgrimage.
Some 1.6 million pilgrims arrived in the kingdom by air, according to the Saudi Passports Department on Tuesday.
Saudi Arabia is home to the holy city of Mecca, Islam's most sacred site, where Muslims go each year to perform the Hajj, which begins on Wednesday.
Devout Muslims are expected to perform the Hajj, one of Islam's five pillars, at least once in their lifetime, provided they are fit enough and have the financial means to do so.
The pilgrimage has long been entangled in Saudi Arabia's politics.
This year, the dispute between Qatar and four Arab nations, led by Saudi Arabia, prompted Doha to accuse Riyadh of creating obstacles for Qatari pilgrims after it cut economic and transport links with its smaller neighbour.
Saudi Arabia later opened its border crossing with Qatar, allowing 1300 Qataris to perform the annual ritual.
The pilgrimage has seen several accidents over the years.
In 2015, 769 pilgrims died in a stampede during the symbolic stone-throwing ritual near Mecca, according to Saudi official figures.
A DPA tally and other independent reports, however, indicated that around 2,000 pilgrims died in the incident, making it the worst Hajj tragedy on record.
In 1990, 1426 pilgrims died in a stampede inside a tunnel after its ventilation system broke down.