The suspects were allegedly implicated in plotting "chaos" during Ashura.
Karbala: Iraq has arrested 73 al Qaeda-linked suspects officials said were implicated in plotting "chaos" during Ashura in Karbala, as two million pilgrims thronged the Shi’ite shrine city on Thursday.
The arrests underscored fears of violence during the 10-day rituals that culminate on Friday, in a key test for Iraqi security forces ahead of a complete withdrawal of American troops in a year.
Vehicle traffic in Karbala came to a virtual standstill as pilgrims were made to walk to the shrines of the revered Imams Hussein and Abbas, while all visitors were searched at checkpoints.
"We were able to destroy 14 terrorist cells and arrest 73 people, including 37 wanted persons," Karbala provincial council chief Mohammed al-Mussawi said.
"We seized lots of weapons, IEDs (improvised explosive devices), explosives belts and equipment.”
"If they had been able to mount their attacks during the pilgrimage, it would have created chaos. Karbala is the main target for terrorists during Ashura."
Mussawi said those arrested were suspected members of al Qaeda.
Speaking on Wednesday, the Iraqi Army commander responsible for security in five provinces including Karbala said those detained were implicated in an al Qaeda-linked group called the Boys of Heaven.
General Othman al-Ghanimi said a total of 80 suspects had been arrested.
Mussawi said the number of pilgrims in Karbala for the commemorations had reached two million, 238,000 of them from abroad.
Karbala police spokesman Major Alaa Abbas reported no incidents in the city so far. He said tight security arrangements would remain in force until the pilgrims had headed home after the ceremonies.
Around 28,000 soldiers and police are currently securing Karbala, with another 7,000 available if needed.
This year marks the first time Iraqi troops have been in sole charge of the ceremonies` security. While American troops have not provided ground forces for Ashura in several years, they have helped with surveillance and reconnaissance.
In previous years, Ashura has been a target for Sunni Arab extremists, who see the 10-day ceremonies as symbolically highlighting the split between Islam`s two main branches.
This year, a total of 18 pilgrims have been killed since the rituals began on December 8, police said.
Seven co-ordinated roadside bombs hit one procession in the town of Dujail, north of Baghdad, killing one person and wounding seven.
The deadliest Ashura attacks were in March 2004 when near-simultaneous bombings in Karbala and at a Shi’ite mosque in Baghdad killed more than 170 people.
Violence levels have dropped dramatically since then, however, and are also much lower than in 2006 and 2007, when communal bloodshed engulfed much of the country. The number of Iraqis killed in violence in November was the lowest in a year for the second month running.
The rituals commemorate the killing of Imam Hussein, a grandson of the Prophet Mohammed, by armies of the caliph Yazid in 680 AD. Tradition holds that the revered imam was decapitated and his body mutilated.
Black flags, representing the sorrow of Shi’ites during the rituals, were visible across the city alongside pictures of Imams Hussein and Abbas, both of whom are buried in Karbala.
Ceremonies begin with devotees drenched in blood after ritually slicing their scalps and flaying themselves with chains attached to sticks, symbolically showing their guilt and remorse for not defending Hussein.
Now-executed dictator Saddam Hussein`s Sunni-dominated regime barred the vast majority of Ashura commemorations throughout his rule until his overthrow in the US-led invasion of 2003.
Shi’ites make up around 15 percent of Muslims worldwide. They represent the majority populations in Iraq, Iran and Bahrain and form significant communities in Afghanistan, Lebanon, Pakistan and Saudi Arabia.