Chanting “Allah Akbar", worshippers from 189 countries advanced in waves around Jamrat Al Aqaba, the largest of three adjacent pillars, in the rite that will continue at least until Saturday.
Roads inside Mina and those leading to the city were blocked with pilgrims trying to reach the camps set up to receive them according to their country of origin.
The pilgrims had stopped to collect stones overnight in Muzdalifah, another holy town that comes to life only during the five days of the annual hajj pilgrimage, before heading to Mina valley.
Men and women were seen bending to the ground to choose their stones which they carried in empty water bottles or in plastic bags.
The stones must be slightly larger than a chick pea.
The stay in Mina used to mark the most dangerous phase of the Hajj for the Saudi authorities as it has been marred by deadly stampedes in the past as well as by fires in tent camps.
The stoning area has also been expanded to avoid overcrowding.
Saudi authorities have built a five-level structure around the three sites, allowing for a smooth flow of pilgrims.
King Abdullah bin Abdulaziz, Custodian of the Holy Mosques, who performed the vows in Mina, discussed instability in the region with officials and urged security officers to “act against those who would dare harm the security, unity and sovereignty” of the kingdom.
After they stone the pillars, pilgrims end their Ihram by shaving or cutting their hair for men while women trim the length of a finger-tip from one strand of hair. Ihram is a state in which pilgrims wear special clothing — two-piece white seamless garments for men and any loose dress for women, who completely cover themselves except for their hands and faces. AP