Hajj retraces the last steps of the Prophet Mohammed (PBUH) and also honours the prophets, Abraham (AS) and Ishmael (AS).
The movement began with pilgrims from Adamawa and Oyo states who had hitherto been camped along with their counterparts from the 36 states and FCT in Muna, few kilometres away from the Holy city of Makkah. By Thursday, more than 1.6 million people had arrived in Saudi Arabia for the pilgrimage, AFP reported.
Muslim pilgrims walk towards Namirah mosque on Arafat Mountain, during the annual hajj pilgrimage, outside the holy city of Mecca on Sunday.
The interior ministry said on Saturday that the number of pilgrims arriving in Makkah had already surpassed the two million mark, mostly from overseas including large contingents from Egypt, India, Pakistan and Bangladesh.
Muslim pilgrim gather on Mount Mercy on the plains of Arafat during the annual haj pilgrimage, outside the holy city of Mecca, Saudi Arabia August 20, 2018. "Two years ago, I performed haj for the former, and last year for the later", said the 32-year-old from Deir al-Zor.
Qatar accused Saudi Arabia of barring its citizens from this year's Hajj, which Riyadh denies, saying a diplomatic dispute is not stopping Qataris from making the pilgrimage to Mecca.
They do it at the very beginning of Hajj and at the very moment when the Hajj ends.
For those undertaking annual haj pilgrimage and reach the valley of Mount Arafat, it is the time for celebrations and feasting.
Muslims traditionally slaughter sheep for the three-day Eid al-Azha, a tribute to the prophet Ibraham's sacrifice of a lamb after God spared Hazrat Ismael, his son.
They have cut all ties with Qatar and banned all flights to and from Doha.
Earlier this month, Saudi Arabia said it would provide Hajj visas for Qatari nationals on arrival, according to The National website.
Hajj will officially end on Tuesday, when Saudi Arabia celebrates Eid-ul-Azha, with the Korbani sacrifices.
Saudi Arabia has drawn harsh criticism for a crackdown on political dissent since the appointment previous year of Crown Prince Mohammed bin Salman, whose modernisation campaign has grabbed headlines around the world.
"After that, we will watch the movement of the pilgrims from Makkah to Madinah to pay homage to Prophet Muhammad (peace be upon him) and pray at his mosque", he said.