Draped in white robes to symbolize purity and the equality of mankind under God, nearly 3 million Muslims from all over the world gathered Friday in Mecca, on the eve of the start of the annual hajj pilgrimage. Male pilgrims, wearing two-piece seamless white robes, and women, covered head to foot except for their hands and faces, circled the sacred Kaaba stone structure seven times inside the Grand Mosque, which Muslims face during their five daily prayers. A pillar of the Muslim faith, the hajj is packed with symbolism and ritual aimed at cleansing the soul of sin. Every able-bodied Muslim who can financially afford to must perform it at least once in his or her lifetime. For Turkish pilgrim Omar Danis, the journey to Mecca was a dream come true. "As soon as I saw the Kaaba, I felt a light in my heart. I kneeled down to thank God as my tears flowed," said Danis, in his 60s. Saudi Arabia has deployed some 100,000 security personnel to keep order during the five-day pilgrimage, which starts Saturday. Roadblocks have sprung up on all roads leading to Mecca, and police check for hajj permits from Saudi nationals and for passports from pilgrims who arrived from abroad. Security is high also because the hajj comes just over a week after terror attacks in Mumbai, India's financial capital, in which suspected Islamic militants killed 171 and injured more than 300 others in assaults on upscale hotels, a restaurant and other sites across the city. Saudi authorities have said they have no indication of any threats this year. There have been scores of arrests ahead of hajj, but they have targeted people allegedly trying to defraud pilgrims or breaking other regulations connected to the hajj. Among them were two Egyptians who allegedly operated an illegal hajj tour company. Pilgrims are required to come to Mecca through recognized tour companies, a system aimed at managing the huge numbers. Iranian pilgrim, Ismaeil Bahramian, said the pilgrimage is a crowning moment in a Muslim believer's life. "Here, there is no difference between the rich and the poor, white and black. We are all brothers and sisters," said Bahramian, at the hajj for the first time, choking back emotion. "Truly, this is the original home of God. It is an honor to be a guest of God here." Ambulances and medical centers have been readied to deal with emergencies. Stampedes or fires at past pilgrimages have killed hundreds. At the Grand Mosque, when loudspeakers blared the midday call to prayer, the procession around the Kaaba ground to a halt. Pilgrims paused to listen to verses from the Quran, Islam's holy book, then prostrated in prayer toward the black cubic structure. The hajj culminates Sunday, when the pilgrims gather on Mount Arafat, 12 miles (20 kilometers) from Mecca in the desert, where Islam's Prophet Mohammed is said to have given his last sermon 14 centuries ago. At Arafat, pilgrims offer prayers from noon to shortly after nightfall in a ritual that's interpreted as a foretaste of the Day of Judgment, when Islam says every person will stand before God and answer for his deeds. The hajj will continue for several more days, as pilgrims carry out a ritual symbolizing the stoning of the devil at the nearby plain of Mina, before concluding on Wednesday. Just 50 years ago, the pilgrimage attracted only about 10,000 people. This year, Saudi embassies world over have issued nearly 2 million visas. Just under a million pilgrims also come to the hajj from Saudi Arabia. Many others are believed to come without proper documents.