BAGHDAD, Iraq -- Gunmen took aim at multitudes of Shiite Muslim worshipers marching through this besieged capital yesterday, killing at least 22 and leaving hundreds injured in a vivid illustration of the sectarian violence driving Iraq toward open civil war.
Panicked pilgrims, including women in full-length black robes, scattered in terror as opportunistic gunmen fired from positions on rooftops, inside buildings and on the streets. Security officers and Shiite militiamen returned fire during rolling gunbattles along the routes to the worshipers' destination, a major Shiite shrine.
Iraqi television showed images of pilgrims diving for cover behind parked cars and buildings as ambulances ferried off victims. Authorities reported that security forces killed several of the snipers.
Despite the gunplay, U.S. and Iraqi officials argued that a draconian weekend security clampdown, including a two-day ban of most vehicular traffic in the capital, helped avert a higher death toll as more than 1 million Shiites headed on foot to the shrine. No major attack was reported at the bustling shrine site.
An Interior Ministry official labeled the security dragnet, which also included the posting of thousands of police and troops at the shrine and along its access roads, as "an extraordinary success," given the potential for mass casualties in the incendiary climate of contemporary Iraq.
Last year, almost 1,000 pilgrims were killed during a stampede sparked by fears of a suicide attack that culminated in a human crush on the Aima Bridge over the Tigris River. Many of the victims, including numerous women and children, were forced into the river and drowned.
This year, police closed the Aima Bridge and funneled worshipers to two other spans in a move aimed at dispersing the masses and providing greater protection.
The U.S. military praised the "comprehensive security plan" devised by Iraqi military and civil leaders.
"These acts against innocent civilians are deplorable, but Iraqi security forces did an excellent job in preventing more needless loss of innocent civilian lives," U.S. Army Maj. Gen. James D. Thurman, who leads American forces in Baghdad, said in a statement.
Officials referred to the lack of car bombs and suicide strikes as significant accomplishments during the two-day religious ceremony, which attracted masses of faithful to the gold-domed shrine in the northern Baghdad neighborhood of Kadimiyah. Four mortar strikes were reported in the capital, an official said, but none were fatal.
Authorities set up checkpoints as far as 3 miles from the shrine and searched everyone entering the holy site for weapons and concealed suicide devices. Foot patrols hunted for clandestine launching pads used to fire mortar rounds and Katyusha rockets, staples of the insurgent arsenal.
Officials said those killed yesterday were shot en route to or from the shrine as they walked through neighborhoods populated mostly by Sunni Muslims, who are fighting the country's Shiite majority in an increasingly bloody internecine struggle. Many worshipers walked for miles, some barefoot, to pay homage to Moussa al-Kadhim, who died more than 1,200 years ago and is one of the 12 revered imams of the Shiite sect.
Gunmen shot and killed at least seven other pilgrims along a highway Friday, officials said, before the vehicle ban went into effect.
Authorities said 302 people were injured during this year's pilgrimage, including gunshot victims and shrapnel casualties from mortar strikes. It appeared that many were hurt in other ways, such as falling while scrambling from the gunfire.
Baghdad, whose residents long boasted of religious tolerance, is increasingly a city of Sunni and Shiite enclaves. Many have left once-mixed neighborhoods for the relative safety of zones dominated by one or the other sect and patrolled by corresponding militiamen. Others have been forced out or killed.
But many pilgrims headed to the Kadimiyah shrine had no choice but to pass through largely Sunni districts brimming with resentment about the Shiite political domination that followed the U.S.-led ousting in 2003 of Saddam Hussein, a Sunni tribesman who favored his religious brethren.
"I left my house at 10 p.m. because it is much safer and the weather is cooler," said Ali Hassan, 18, a laborer who arrived safely at the shrine in the predawn hours yesterday. "But this morning we heard some gunshots aimed at the pilgrims, and some were hit."
Hassan, who was not injured, said he made the pilgrimage in honor of his older brother, Sadeq, who perished in the Tigris during last year's human stampede.