Photo gallery: Annual Hajj pilgrimage

Muslim worshippers praying around the holy Kaaba at the Grand Mosque in Mecca, Saudi Arabia, on August 29, 2017.

Muslim worshippers pray around the holy Kaaba at the Grand Mosque in Mecca, Saudi Arabia, on August 29, 2017.

Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

A young girl looks on as Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

A Muslim pilgrim takes a selfie at the Grand Mosque in the holy Saudi city of Mecca, early on August 30, 2017, on the eve of the start of the annual Hajj pilgrimage.

A Muslim worshipper cries as he kisses the holy Kaaba at the Grand Mosque in Mecca, Saudi Arabia, on August 29, 2017.

Muslim pilgrims walk at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

A Muslim pilgrim takes a selfie at the Grand Mosque in the holy Saudi city of Mecca, early on August 30, 2017, on the eve of the start of the annual Hajj pilgrimage.

Water is sprayed to cool down the heat ahead of Hajj in the tent city of Mina, Mecca, Saudi Arabia, on August 29, 2017.

Water is sprayed to cool down the heat ahead of Hajj in the tent city of Mina, Saudi Arabia, on August 29, 2017.

Muslim pilgrims pray at the Grand Mosque in the holy Saudi city of Mecca, on August 29, 2017, on the eve of the start of the annual Hajj pilgrimage.

Saudi police officers stand in line during a security preparation in the tent city of Mina, Saudi Arabia, on August 29, 2017.