Millions in Mecca Start Hajj

(CNN) — Millions of Muslims from around the world were in the holy city of Mecca on Saturday for the first day of Hajj, the annual pilgrimage that every able-bodied Muslim is expected to perform at least once in his or her life.

Dressed in white and following in the footsteps of the prophet Mohammed, pilgrims climbed Mount Arafat, just outside the Saudi Arabian city.

Hajj, a five-day pilgrimage, consists of a series of detailed rituals in Mina, Muzdalifa, Arafat and Mecca.

It is one of the five pillars of Islam.

Will this year’s Hajj have an ‘Arab Spring’ effect?

This year’s pilgrimage is unique as it is the first to happen since the Arab Spring began last year.

Some experts are watching for potential flare-ups in Saudi Arabia, a country governed by an unelected royal family and where freedoms are limited.