( AP ) - Millions of Muslims from around the world gathered in Mecca Sunday for the start of the annual Islamic hajj pilgrimage, as the Saudi Interior Ministry announced tough security precautions.
Men and women draped in white robes circled the Kaaba, Islam's holiest site, seven times in a ceremony anticipating the official start of the pilgrimage on Monday.
King Abdullah has invited 1,000 guests to this year's hajj, including Iranian President Mahmoud Ahmadinejad.
Over the next two days, an estimated 2.5 million pilgrims will move out of Mecca to Mount Arafat for Tuesday's climax of symbolically stoning the devil.
By Friday, more than 1.6 million pilgrims had arrived in Mecca, according to the Central Hajj Committee. The Health Ministry said about 254 pilgrims, many who were elderly, have died of natural causes since arriving.
The pilgrims are massed in tent cities on the outskirts of Mecca. For many believers, the hajj is a once-in-a-lifetime chance to cleanse their sins in what is one of the most important rites for Muslims.
This year's hajj takes place amid increasing worries across the Islamic world over the bloodshed in Iraq and Afghanistan and recent terror attacks by al-Qaida-linked groups, including last week's twin suicide bombings in Algeria that killed at least 37 people.
Tensions also have increased between the two main sects of Islam, Sunnis and Shiites, who come together in the five days of hajj rituals centered around Mecca, the traditional birthplace of Islam's Prophet Muhammad.
Saudi Arabia and other Gulf Arab countries - who are all U.S. allies - have been worried over Iran's increasing regional influence. But the king's invitation to Ahmadinejad appeared to reflect a readiness from Saudi Arabia, a majority Sunni country, to reach out to its Shiite-dominated neighbor. It comes about a week after the a U.S. intelligence report said Iran had ended a nuclear weapons program four years ago.
Saudi Interior Minister Prince Nayef bin Abdul-Aziz said the kingdom is capable of maintaining security and preventing any attempt to threaten the safety of the pilgrims.
"We will not allow for the problems in other countries to be reflected here during this hajj season," he said in a news conference late Saturday.
Maj. Gen. Saleh Mohammed al-Shihri, commander of the Central Control of the Hajj Security, said 1,150 cameras have been placed in several areas to monitor the area. Several helicopters, fitted with these cameras, will also hover over the pilgrims.
Nayef said no extra security precautions will be put in place for Ahmadinejad. The Iranian leader was scheduled to arrive in Mecca on Monday, Iranian state media has reported.