The Hajj pilgrimage kicked off on Monday with nearly 2 million Muslims from around the world performing the holy rituals.
The pilgrims will spend the day at Mina before heading to Mount Arafat in the early hours of Tuesday.
The General Directorate of Passports said 1.6 million pilgrims have arrived in Saudi Arabia through its land, sea and air ports.
Among them are 4,951 pilgrims who will perform the Hajj at the expense of Custodian of the Two Holy Mosques King Salman bin Abdulaziz. They include relatives of martyrs from Palestine, Yemen, Syria and other countries.
Interior Minister Prince Abdulaziz bin Saud bin Naif and National Guard Minister Prince Abdullah bin Bandar underscored the readiness of the security forces at the holy sites.
In 2020, amid worldwide coronavirus lockdowns, Saudi Arabia limited the pilgrimage to a few thousand citizens and local residents. This is the first year it returns to full capacity.
The Hajj begins with the circling of the Kaaba in the holy city of Makkah counter-clockwise seven times while reciting prayers. Pilgrims then walk between two hills in a reenactment of Hagar's search for water for her son, Ismail.
All of this takes place inside Makkah’s Grand Mosque — the world's largest — which encompasses the Kaaba and the two hills.
The next day, pilgrims head to Mount Arafat, some 20 kilometers (12 miles) east of Makkah, where the Prophet Mohammed delivered his final sermon. Here, they stand in prayer throughout the day asking God for forgiveness of their sins in the spiritual high point of the pilgrimage.
Around sunset, pilgrims walk or take buses to an area called Muzdalifa, 9 kilometers (5.5 miles) west of Arafat. They pick up pebbles to use the next day in a symbolic stoning of the devil in the valley of Mina. The pilgrims stay for several nights in Mina in one of the largest tent camps in the world.
The pilgrimage ends with a final circling of the Kaaba and further casting of stones at Mina. Men often shave their heads and women clip a lock of hair, signaling renewal.
The final days of Hajj coincide with Eid al-Adha, or the festival of sacrifice, a joyous occasion celebrated by Muslims around the world. During the three-day Eid, Muslims slaughter livestock and distribute the meat to the poor.