U.S. forces in Iraq on Tuesday undertook a hazardous operation designed to “clear the streets of potential hazards” in order to facilitate the solemn Arba’een pilgrimage to the Husyan and Abbas shrines in Karbala – a Shiite religious observance that had been banned by Saddam Hussein, a Sunni.

A military journalist’s on-the-scene report featured on the official website of the U.S. forces in Iraq described how officers leading a joint patrol of U.S. and Iraqis “walked along the shoulder of the road as cars passed by honking their horns as people waved hello.”

1st Lt. Meghan E. Keefe of the 37th Engineer Battalion (Combat) (Airborne) added that “With their mine detectors, searching for any metal objects that could potentially pose a threat, the engineers moved ahead of … [a] platoon of infantrymen.”

The U.S. troops were performing the risky undertaking because the Shiite pilgrims, to reach their destinations, had to travel “on roadways that, in the past, have had threats imposed on them from improvised explosive devices,” according to Keefe.

Arba’een is the 40th day after Ashura, the martyrdom of the 3rd Iman Husain ibn Ali, the grandson of Muhammad slain in the Battle of Karbala in the year 680. For nearly three decades, public observances of Arba’een were prohibited in Iraq under the Ba’ath government of Saddam Hussein.

In bordering Iran, Arba’een was used as the occasion to embark on a general strike in 1963 to protest the killing of Ayatollah Khomeini supporters in Iran’s holy city of Qom. Khomeini would be arrested that year by the Shah, and exiled the following year. A decade and a half later, Khomeini came to power in the Islamist revolution that still engulfs the country today.

The troops conducting the anti-mine and other protective activities on behalf the Iraqi Shiite pilgrims were from the 37th Engineer Battalion - Joint Task Force Eagle, based at Fort Bragg, North Carolina and the 1-28 Infantry Battalion of Fort Riley, Kansas.

The University of Western Australia’s De-mining Project has described some of the hazards of indentifying the locations of land mines. “Prodding is the most dangerous activity for the de-miner,” according to the UWA .

“The work is carried out from a prone or squatting position where the de-miner probes the ground at an angle of 30 degrees using a bayonet or similar tool. When they encounter a solid object, the dirt has to be carefully scraped away. The de-miner has to keep searching until the object that set off the metal detector is uncovered or removed in the waste. If the metallic object is small, such as a fragment of rusty iron, it can be extremely difficult to find.”

Ironically, the association of U.S. forces with Muslim pilgrimage has an altogether different connotation to the terrorist organization al-Qaida. Its founding leader Osama bin Laden considered the deployment of American troops in Saudi Arabia in 1990 during the Persian Gulf War to be a desecration of the sacred soil of “the land of the two mosques” of Mecca and Medina, where all able-bodied Muslims must perform the Hajj pilgrimage at least once.

It is widely believed to be the impetus for bin Laden’s subsequent focus on masterminding al-Qaida attacks on the U.S. and other Western powers.