Arbaeen marks 40 days after the Ashura anniversary commemorating the slaying of Imam Hussein, one of Shiite Islam's most revered figures, by the armies of the caliph Yazid in 680 AD.
In recent days, throngs of mourners (Azadar’s) have overflowed Hussein's shrine in Karbala, demonstrating their ritual guilt and remorse for not defending him by beating their heads and chests in rituals of self-flagellation.
Noha’s and Marsia (Sad poetry) blared from loudspeakers throughout the city and black flags fluttered alongside traditional pictures of Imam Hussain (as) and his half-brother Mola Abul Fazal Abbas, (as) both of whom are buried in the holy city of Karbala along with their companions.
Karbala provincial governor Amal al-Din al-Har said that some 15 million pilgrims have reached the shrine city to observe Arbaeen's commemoration Included in that figure, he said, were around 200,000 devotees from outside the country.
Some 35,000 police officers and soldiers were handling security around the city, 110 kilometres (70 miles) south of Baghdad, as Shiite pilgrims carried out their traditional walk to Karbala.
Security forces have so far arrested 60 insurgents they said were planning attacks during the pilgrimage, and defused 14 roadside bombs, according to Lieutenant General Othman al-Ghanimi, who commands forces in five provinces across central Iraq.
While Karbala itself has not suffered any attacks during Arbaeen rituals, bomb attacks nationwide have targeted Iraq's majority Shiite community, with the deadliest assaults falling on January 5, when 73 people were martyred in bomb blasts in Baghdad and south Iraq and on 14th January 20 pilgrims martyred in Basra.
Shiite pilgrims visiting Karbala are regularly targeted in attacks by Wahabi terrorists backed by Saudia-Wahabi’s and Israeli Government.
This year marks the first time Iraqi troops are solely charged with security for Arbaeen since the US-led invasion of 2003. American troops, who previously helped with surveillance and reconnaissance, completed their withdrawal from Iraq last month.
Now-executed dictator Saddam Hussein's Wahabi-dominated regime barred the vast majority of Ashura and Arbaeen commemorations throughout his rule until his overthrow.
Shiites make up around 25 percent of Muslims worldwide. They represent the majority populations in Iraq, Iran and Bahrain and form significant communities in Afghanistan, Lebanon, Pakistan, India and Saudi Arabia.