Muslim pilgrims are continuing the ritual of throwing stones at pillars representing the devil, as part of the annual Hajj pilgrimage to Mecca.

Crowds of people took part in the ceremony Monday in the Saudi holy city of Mina. Each pilgrim throws 21 pebbles at each of three pillars. The pilgrims then go to the Great Mosque in nearby Mecca to walk around the Kaaba, a huge cube-shaped structure into which is set the Black Stone, Islam's most sacred relic.

Saudi officials say more than 2.5 million Muslims have made the journey this year to take part in the Hajj, which is the oldest and most sacred ritual of Islam. All physically- and financially-able Muslims are required to make the pilgrimage at least once.

The stoning ceremony began Sunday with hundreds of thousands of pilgrims participating.

Sunday also marked the beginning of Eid al-Adha, or the Feast of Sacrifice, in remembrance of Abraham's near sacrifice of his son.

Saudi Crown Prince Nayef bin Abdel Aziz said a record 1.8 million foreign pilgrims had arrived in the kingdom by Friday, representing 183 nationalities. The foreigners joined hundreds of thousands of Saudi Muslims taking part in the ritual, which is one of the five pillars of Islam.

Most pilgrims visit the holy mosques in Mecca, the birthplace of the Prophet Mohammed, and nearby Medina, where Mohammed was buried about 1,400 years ago. They also gather on Mount Arafat, where the prophet is said to have delivered his last sermon.

The Hajj is being streamed live at youtube.com/hajjlive.