While thousands of security personnel have been deployed around holy sites, drones are also being used to monitor traffic.
The Hajj this year is back to its pre-pandemic levels when nearly 2.5 million people gathered in Mecca.
The pandemic forced downsizing of the Hajj for three consecutive years, with only a few thousand residents in the kingdom taking part under strict social distancing measures in 2020.
There were some 60,000 pilgrims in 2021 and the number rose to 1 million last year.
The Hajj began on Monday and is expected to end on Friday.
Wednesday marks the start of the Muslim Eid al-Adha festival in Saudi Arabia and many other countries.
