A mask-clad woman stands on a ring delineating where worshippers sit around the Kaaba due to the COVID-19 pandemic at the almost empty Grand Mosque in Saudi Arabia's holy city of Mecca, on Tuesday, ahead of the annual Muslim hajj pilgrimage. Photo: AFP

Mask-clad Muslim pilgrims on Wednesday began the annual hajj, dramatically downsized this year as the Saudi hosts strive to prevent a coronavirus outbreak during the five-day pilgrimage.

The hajj, one of the five pillars of Islam and a must for able-bodied Muslims at least once in their lifetime, is usually one of the world's largest religious gatherings.

But this year only up to 10,000 people already residing in the kingdom will participate in the ritual, a tiny fraction of the 2.5 million pilgrims from around the world that attended last year.

Pilgrims walked into Mecca's Grand Mosque in groups to begin the ritual with their first "tawaf," or walk around the Kaaba, a cube-shaped structure draped in gold-embroidered cloth toward which Muslims around the world pray, state television showed.

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

Those selected to take part in the hajj were subject to temperature checks and placed in quarantine as they began trickling into Mecca at the weekend.

State media showed health workers sanitizing their luggage, and some pilgrims reported being given electronic wristbands to allow authorities to monitor their whereabouts.

Workers, clutching brooms and disinfectant, were seen cleaning the area around the Kaaba. Using his bare hands, one worker was shown daubing its outer wall with perfume.

Hajj authorities have cordoned off the Kaaba this year, saying pilgrims will not be allowed to touch it, to limit the chances of infection.

They also reported setting up multiple health facilities, mobile clinics and ambulances to cater to the pilgrims.

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

The foreign press are barred from this year's hajj, usually a huge global media event, as the government tightens access to Mecca. Saudi authorities initially said only around 1,000 pilgrims residing in the kingdom would be permitted for the hajj, but local media reports say as many as 10,000 will be allowed to take part.

Some 70 percent of the pilgrims are foreigners residing in the kingdom, while the rest are Saudi citizens, authorities said. 

All worshippers were required to be tested for coronavirus before arriving in Mecca and will also have to quarantine after the pilgrimage as the number of cases in the kingdom nears 270,000.