Hajj - the annual Muslim pilgrimage to Mecca - has begun, but under dramatically different circumstances due to the coronavirus outbreak.

One of the five pillars of Islam, the Hajj is required for all Muslims who are physically or financially capable of undertaking it at least once in their lifetime and is usually one of the world's largest religious gatherings.

But this year, only up to 10,000 people already residing in Saudi Arabia will participate in the five-day pilgrimage, a tiny fraction of the 2.5 million pilgrims from around the world that attended last year.

"There are no security-related concerns in this pilgrimage, but [downsizing] is to protect pilgrims from the danger of the pandemic," said Khalid bin Qarar Al-Harbi, Saudi Arabia's director of public security.

Pilgrims will be required to wear masks and observe physical distancing during a series of religious rites that are completed over five days in the holy city of Mecca and its surrounding areas in western Saudi Arabia.

Al Jazeera's Jamal Elshayyal reports.