Baghdad, Iraq (CNN) -- Two Shiite pilgrims were killed in a roadside bombing in Baghdad on Saturday afternoon, the latest strike targeting people marking Ashura, one of the most important annual holy periods for Shiite Muslims across the globe.
Eight other people were wounded in the strike, which occurred in the New Baghdad district of southeastern Baghdad, Interior Ministry officials said.
The incident comes amid a large troop presence on the streets of Baghdad and several outlying regions, such as the holy city of Karbala, to protect Shiite pilgrims from attacks.
Hundreds of thousands of the pilgrims are expected in Baghdad and Karbala for the commemoration, which reaches its peak over the next 24 hours.
The period commemorates the martyrdom of Hussein, the grandson of the Prophet Mohammed who was killed in battle in Karbala in 680, one of the events that helped create the schism between Sunnis and Shiites, the two main Muslim religious movements.
From Saturday evening until Sunday in Karbala and Baghdad, Shiite pilgrims will be chanting, beating their breasts in penance, cutting themselves with daggers or swords and whipping themselves in synchronized moves until next morning.
Brig. Gen. Qassim Atta, the spokesman of Baghdad Operations Command, told CNN around 100,000 security forces in and around Baghdad are on full alert. Four security rings were in place around Kadhimiya in northwestern Baghdad, where more than one million visitors are expected Saturday night and Sunday, he said.
Atta said 300 female security forces were stationed at a number of checkpoints to ensure the proper searching of women.
Gen. Othman al-Ghanimi, the Karbala police commander, told CNN that 25,000 Iraqi security forces from the army and police were deployed in Karbala province.
He said the region was divided into nine security sections and, as in Baghdad, four main security rings were set up around the city. Pilgrims must pass through at least four checkpoints before reaching the holy shrine of Imam Hussein.
Around one million pilgrims are expected to be in Karbala.
The marking of Ashura was banned for many years under Saddam Hussein, but observances resumed after he was toppled in 2003.
In the first public Ashura demonstrations in Karbala after Saddam's fall, in 2004, violence erupted and authorities blamed Sunni extremists. In 2005, nearly 1,000 Shiite pilgrims were killed in a stampede over a bridge in northeastern Baghdad, a panic triggered by rumors of a suicide bomber in the crowd.
This year, dozens of Shiite pilgrims were killed in a number of attacks across the country. The Iraqi government believes al-Qaeda in Iraq and other Sunni extremist insurgent groups are behind these attacks.
In another incident on Saturday, officials said local police officers were wounded when a roadside bomb struck their convoy in Zafaraniya district in southeastern Baghdad on Saturday.
-- CNN's Mohammed Tawfeeq contributed to this report.