By Agence France-Presse More than two million Muslims took part in the symbolic stoning of the devil Tuesday in Saudi Arabia, the last major ritual of the hajj pilgrimage that heralds the start of the Eid al-Adha feast. Muslims on the annual hajj pilgrimage, one of the five pillars of Islam, made their way across the Mina valley of the western Saudi Arabian Mecca province, many carrying pebbles in plastic bottles.   Pilgrims clad in white threw seven stones each at a pillar symbolizing Satan, shouting "Allahu akbar" ("God is greatest") under the watchful eyes of security forces. Large fans sprayed water over the crowd as temperatures climbed to 44 degrees Celsius (111 Fahrenheit). "Thank God it hasn't been too crowded this year. There hasn't been a big rush," said Mohammed Osman, 27, who regularly attends hajj. Mina was the site of a 2015 stampede which saw more than 2,300 pilgrims crushed or suffocated to death. Authorities have since reinforced safety and security measures. "We are under God's protection," said May Khalifa, a 37-year-old Egyptian Muslim living in Riyadh. "Despite the exhaustion, I'm enjoying my first hajj," she said, lifting her small bag of stones. The hajj is one of the world's largest Muslim gatherings and drew this year nearly 2.4 million pilgrims to Saudi holy sites. 'Great honor' Roads from Muzdalifah -- another holy site where pilgrims spent Monday night -- to Mina were littered with plastic water bottles as sanitation workers scrambled to remove them. Bangladeshi Moueeneddine Ahmed, 35, complained of the scorching heat but said he was "very excited" to take part in the stoning of the devil ritual. In keeping with customs, he said he would then "shave his head" and trade the white seamless robe he wore for the hajj for his "normal clothes". Ahmed also praised the Saudi government for keeping the peace throughout the hajj. "There's a lot of security. Very disciplined," he said. Tens of thousands of security forces, including police and civil defense, have been deployed for hajj, according to Saudi authorities. Saudi Arabia's King Salman made the trip to Mina on Tuesday and was seen on state-run television observing worshippers from the window of a high-rise. The king, who took to Twitter to say it was a "great honor" to welcome the pilgrims to Saudi Arabia, later paid homage to Saudi soldiers in a televised speech. "On this day, we must remember our martyrs and heroes, who gave their lives to protect their faith and country," the king said, in an apparent reference to the war in Yemen. Saudi Arabia leads a regional military alliance battling Shiite Huthi rebels in Yemen, where more than three years of war have killed thousands and triggered what the UN calls the world's worst humanitarian crisis. Public health measures The hajj retraces the steps of the Prophet Mohammed on his last pilgrimage to Mecca. It is one of the five pillars of Islam which every Muslim is required to complete at least once in their lifetime if they are healthy enough and have the means to do so. Muslim tradition holds that pilgrims must throw seven stones each at a pillar representing Satan on the first day of Eid al-Adha, which comes after two days of prayer and meditation. The stoning ritual is not without risk, as millions of pilgrims converge on a tight space. Since 2004, authorities have expanded the site and replaced the pillar by walls to accommodate the growing number of pilgrims, who can now reach Mina via multiple bridges. Muslims traditionally slaughter sheep for the three-day Eid al-Adha, a tribute to the prophet Abraham's sacrifice of a lamb after God spared Ishmael, his son. They will consume some of the meat and give the rest to poor people unable to buy food. Pilgrims can purchase coupons from the Saudi government, which organizes the slaughter and freezing of the meat to avoid public health problems. Revenues from the coupons are considered "zakat", or a charity donation, another pillar of Islam.