Muslim pilgrims arrive to pray at the Mountain of Mercy (formally known as Mount Arafat) during the Hajj, in Arafat, Saudi Arabia, on October 24, 2012.

Muslim pilgrims pray on a rocky hill called the Mountain of Mercy, on the Plain of Arafat near the holy city of Mecca, in the early hours of Thursday, Oct. 25, 2012.

Pilgrims climb the Mountain of Mercy on Oct. 25, 2012.

Muslim pilgrims wait for the start of prayers at the Grand Mosque in the Saudi holy city of Mecca on October 22, 2012.

Muslim pilgrims leave the Grand mosque after the noon prayer in Mecca, Saudi Arabia, on Oct. 22, 2012.

A Muslim pilgrim gestures as lightning strikes in the background at the top of Mount Noor where Muslims believe Prophet Mohammad received the first words of the Koran through Gabriel, during the annual haj pilgrimage in the holy city of Mecca, Oct. 21.

Muslim pilgrims pray at the top of Mount Noor, Oct. 21.

A Muslim pilgrim gestures at the top of Mount Noor, Oct. 21.

Saudi police officers monitor screens connected to cameras, at the Command and Control Center in Mina, outisde the holy city of Mecca, on November 7, 2011, as millions of Muslim pilgrims take part in the annual hajj.

An aerial view shows Muslim pilgrims walking around the Kaaba in the Grand Mosque in the holy city of Mecca during the annual Hajj pilgrimage rituals on November 7, 2011.

Tens of thousands of Muslim pilgrims move around the Kaaba, seen at center right, inside the Grand Mosque, during the annual Hajj in Mecca, Saudi Arabia, Oct. 31, 2011. The annual Islamic pilgrimage draws 2.5 million visitors each year, making it the largest yearly gathering of people in the world. The Hajj will officially begin on Nov. 5.

Pilgrims circle the Kaaba at the Al-Masjid al-Haram in Mecca.