At the cemetery where the Prophet Muhammad's family is buried, an Iranian Shi'ite Muslim pilgrim overcome with emotion was jerked by a Saudi soldier, who barked a sharp order: "Stop crying!" The soldier, a gun at his hip, then hovered over the pilgrim as he wrapped up his prayers to make sure he didn't start weeping again. The Baqee cemetery is where the bitter rivalry between Sunni powerhouse Saudi Arabia and Shi'ite Iran gets personal. Iranians and other Shiites flock to the graves to pay respects to several revered descendants of Islam's prophet, while Saudi soldiers and morality police try to prevent dramatic displays of fervent praying or weeping. Shi'ites' prayer books are snatched away, they are ordered to read only Saudi-approved verses written on billboards at the site, and groups of worshippers are broken up. Part of the reason for the heavy restrictions is religious. Saudi Arabia's strict version of Sunni Islam, called Wahhabism, considers customs like crying - or even praying - at gravesites and revering saints repugnant because it smacks of idolatry. In fact, many Wahhabi clerics consider Shi'ites heretics. But beyond the religious practices lies politics. The two countries have been locked in a struggle for influence across the Middle East. Saudi forces have been fighting for more than a month with Shi'ite rebels on the border with Yemen who it claims are backed by Tehran. The kingdom accuses Iran of fueling conflicts in Lebanon, the Palestinian territories and Iraq with its support for militant groups. Saudi Arabia, an oil-rich US ally, also appears increasingly worried over Iran's nuclear standoff with the West. Saudi Foreign Minister Prince Saud al-Faisal expressed rare direct concern over Iran's nuclear program in a recent interview with Western media - prompting angry comments by some Iranian officials for the kingdom to stay out of its business. Mahdi Habibolahi, an Iranian who visited the Baqee after performing his hajj pilgrimage last month, sees a message in the harassment he and fellow Shi'ites face. "Maybe they want to give us a warning, that you are different you should be careful, you shouldn't interfere (in the region's politics)," said Habibolahi, an English teacher. The Baqee is on a large piece of land in front of the mosque that encloses the Prophet's tomb in the holy city of Medina. Locked behind high marble walls and iron gates in the Baqee lie thousands of relatives, companions and descendants of the Prophet - including four "imams," the saint-like figures that Shi'ites believe should have been the successors of Muhammad as leaders of the Islamic world. The presence of the imams draws Shi'ites from around the world throughout the year, but particularly in the days after hajj. Iranian pilgrims organize an annual large prayer ceremony at the site. Sunnis consider those buried in the Baqee respected figures, but don't recognize the imams' authority. Elaborate prayers and weeping at gravesites are not as common a practice among most Sunnis. For Wahhabis, it is an anathema - a suggestion that some earthly figure, even one close to Muhammad, could be the object of veneration. Once the burial sites at the Baqee were marked with mausoleums and elaborate gravestones. But those were demolished in the early 20th century by Wahhabis. Today the cemetery is a bare stretch of dirt and sand, with graves' locations designated only by raw, unengraved rocks or raised piles of earth - the way cemeteries are throughout Saudi Arabia. Zeenat Bu Ali, a Quran teacher from Iran in Saudi Arabia for her first pilgrimage, said she was moved to tears when she saw the Baqee's sparseness. "I see the green dome on top of the Prophet Muhammad's tomb and I expect the same thing for our imams," she said. "Why does it have to be so dark?" Bu Ali was only able to see the cemetery through the honeycomb of a metal fence. Women are prohibited from entering the Baqee, because Wahhabis deem them too "emotional" and more likely to cause a scene. Dozens of women hang on the gates begging the soldiers for a glimpse of the gravesite. Saudi security grudgingly allows men to enter the site, but only during a short period each day, and it closely monitors those who enter to ensure they don't go beyond simple, quick prayers. Saudi guards "complain about everything," Habibolahi said. "If someone wants to pray loudly, they say 'lower your voice.' They say, 'don't face this way, you should face that way.' They are so concerned about all details, and unfortunately they are not very polite." The soldiers break up small groups praying together and try to engage the Shi'ites in theological debates. All Shi'ites are restricted. Members of Saudi Arabia's Shi'ite minority scuffled with security forces there early in the year. But with the Iranians, it takes on distinctly political overtones. Saudis "think that Shi'ites are kaffir (infidels) and should be killed and removed from the world," said Ahmed Menai, an Iranian cleric who guides groups of his countrymen on pilgrimages. So Iran's "going towards knowledge or having nuclear technology or power is very harmful for them," he said in English then added, referring to Israel's suspected nuclear arsenal: "They tolerate this for Zionism, but they can't tolerate this for Shi'ite people. They think that we are their enemy, but we are not their enemy." Menai sees the hand of the US behind the Saudi-Iran rivalry, saying Wahhabis' hatred for Shi'ites helps the Americans rally Sunni nations against Iran's growing influence. "The United States saw this as a good way to make a disparity between Muslim people," he said. At the same time, Iran does see political opportunities in the religious rites of the pilgrimage, which is supposed to be a time of Muslim unity. Protests are held annually at the Iranian camps at hajj posting political signs and chanting anti-US slogans. Before this year's hajj, Iran's supreme leader urged Iranian pilgrims to acquaint others with the "Islam of the Islamic Republic of Iran." Saudi officials replied that countries should not try to "politicize" the hajj. Iranian protests during the hajj turned into clashes with Saudi security in 1987 that killed several hundred people.