SEE - August 20th: More than 2 million pilgrims from around the world braved stormy weather in Saudi Arabia on Sunday to begin the annual hajj ritual. They all arrived by Monday morning at Mount Arafat.
Worshippers arrived in the kingdom last week for the five-day ritual - a once-in-a-lifetime religious duty for every able-bodied Muslim who can afford it, which retraces the route Prophet Mohammad took 14 centuries ago.
Some pilgrims prayed at the Grand Mosque before heading to the Mina area or towards Mount Arafat, east of Mecca, where the Prophet is believed to have delivered his final sermon to followers.
Eid al-Adha, or feast of the sacrifice, begins on Tuesday, when pilgrims begin three days of casting stones at walls in a symbolic renunciation of the devil.
The authorities have been preparing for months to ensure pilgrims' safety, Health Minister Tawfiq al-Rabiah told Reuters, with more than 30,000 health workers operating 25 hospitals and offering free medical services, including complex procedures like open heart surgery.
"Praise to God, everything now is under control and health conditions are excellent," he said in an interview at Mina Public Hospital.
Saudi Arabia stakes its reputation on its guardianship of Islam's holiest sites - Mecca and Medina - and organising the pilgrimage.
The interior ministry has put in place measures to confront any security threat from militant attacks to political protests, but no specific threats have been detected, a spokesman said on Saturday.