MECCA (Reuters) - More than two million pilgrims participating in the haj this week began returning to Mecca on Sunday for final prayers as the world s largest annual gathering of Muslims winds down. Senior Saudi officials said the rituals, which have in the past seen deadly stampedes, fires and riots to which authorities sometimes struggled to respond, had gone off without incident. Mecca province governor Prince Khaled al-Faisal, who heads the central haj committee, called this year s pilgrimage a success.  I am proud today to have offered these services and I am proud of all my brothers who participated and I am proud of each pilgrim who came to this land and assisted in the success of this season,  he told reporters in Mina, east of Mecca. Thousands of pilgrims participated in a symbolic stoning of the devil, part of the haj rituals, in Jamarat before returning to Mecca. By nightfall, Mecca s Grand Mosque was crowded with worshippers. Saudi Arabia stakes its reputation on its guardianship of Islam s holiest sites and organizing the pilgrimage. More than 2.3 million pilgrims came to Saudi Arabia this year, most of them from abroad, for the five-day ritual. Attendance is a religious duty, once in a lifetime, for every able-bodied Muslim who can afford it.  The organization was excellent and there was no crowding or anything. Things went well, thanks to God,  said Yemeni pilgrim Rashid Ahmed. More than 100,000 members of the security forces and 30,000 health workers were on hand this week to maintain safety and provide first aid. A crush in 2015 killed nearly 800 pilgrims, according to Riyadh, when two large groups of pilgrims arrived at a crossroads east of Mecca. Counts by countries of repatriated bodies showed over 2,000 people may have died, including more than 400 Iranians. Tehran sent nearly 90,000 pilgrims to the haj this year after boycotting the event last year amid a diplomatic rift with Riyadh. Saudi Health Minister Tawfiq al-Rabeeah said the pilgrimage had passed without any outbreak of disease, a perennial concern. He told Reuters in an interview late on Saturday that the ministry had also provided care to 400,000 people, including 21 open-heart surgeries.  We are keen to offer excellent service so that the pilgrims return home in good health after completing the haj,  he said. 