Saudi Arabia has deployed tens of thousands of stewards to stop stampedes on one of the most dangerous days of the annual Hajj pilgrimage.
Saudi Arabia has spent millions to make the ceremony safer
More than two million Muslims flocked to the Jamarat Bridge in Mina to hurl stones at pillars representing the spot where the devil appeared to Abraham.
In 2004, 251 pilgrims were trampled to death performing the ceremony.
Tuesday is celebrated by Muslims worldwide as Eid al-Adha, the Islamic day of sacrifice.
The festival remembers Abraham's willingness to sacrifice his son when God ordered him.
'Piece of cake'
The Saudi interior ministry had promised a "special plan" to ensure a smooth flow of pilgrims towards the pillars.
Saudi troops patrolled the area, monitoring crowds, and helicopters flew overhead.
First aid crews and ambulances also gathered under the bridge to deal with those affected by the overcrowding or heat exhaustion.
"It was a piece of cake this year," Mecca native Sulayman Fallata told the AFP news agency.
Saudi Arabia has spent millions of dollars since 2004 to improve safety measures at Mina.
New footbridges with emergency exits were built and three new pillars were erected that were wider and taller than ones used previously, so more pilgrims could pelt rocks at the same time.
A fatwa, or religious edict, was also issued to allow the stoning to begin before the dawn prayer.
Every able-bodied adult Muslim who can afford to make the trip is obliged to perform the Hajj, one of the five pillars of Islam, once in their lives.