What Is The Hajj Pilgrimage? The Annual Muslim Celebration Is One Of The World's Largest Public Gatherings

A stampede outside Mecca has left at least 310 people dead and another 450 injured Thursday, and Saudi officials say casualty numbers may continue to rise as more bodies are recovered. According to CNN, 4,000 workers and more than 200 ambulances have been deployed to help with rescue efforts. The incident happened in Mina, roughly three miles from Mecca, during a ritual called "stoning the devil" where Muslims throw small pebbles at a rock wall to represent their rejection of evil. Unfortunately, stampedes are not unusual for the annual Hajj pilgrimage, which sees millions of Muslims around the world make the sacred journey to the holy city.

The Hajj is one of the five pillars of Islam and takes place from the 8th to 12th days of Dhu al-Hijjah, the final month of the Islamic calendar. The pilgrimage to Mecca is one of the biggest celebrations in Islam and accounts for one of the largest public gatherings in the world. Every adult Muslim who is physically capable and has the financial means is expected to make the journey at least once in his or her lifetime. Often, pilgrims save money for decades to fulfill the Hajj. This year, more than 2 million Muslims are expected to descend upon the holy city in Saudi Arabia.

MOHAMMED AL-SHAIKH/AFP/Getty Images

The five-day pilgrimage follows the life of Islamic prophet Muhammad and involves several intricate rites and rituals. Pilgrims must wear white and abstain practices such as having sex, clipping their nails, and killing animals and plants. Men's heads must be uncovered as should women's faces and hands. One ritual asks pilgrims to walk counter-clockwise seven times around the Kaaba, a massive cube-shaped shrine that determines the direction Muslims must face during prayer.

MOHAMMED AL-SHAIKH/AFP/Getty Images

The "stoning the devil," which takes place on the third day, is considered the most dangerous phase of the Hajj because the location is prone to suddenly taking in large swarms of people. A 2012 reconstruction of the Jamaraat Bridge, a pedestrian walkway in Mina that lets pilgrims throw stones at three pillars, added several levels to accommodate more people and allow for easier access. But even with the expansions, stampedes have been common due to overcrowding. Over the years, thousands have died at this junction. In 2006, at least 363 people died and hundreds more were wounded.

MOHAMMED AL-SHAIKH/AFP/Getty Images

Despite these kinds of incidents, the Hajj continues to grow year after year, as Muslims seek to fulfill their religious duties. As another pilgrimage is marred by a devastating tragedy, the world is keeping Mecca in its prayers.