Baghdad (CNN) -- The commemoration of Ashura, arguably the holiest day on the Shiite Muslim calendar, passed without significant violence in Iraq Sunday.
The peace was a marked contrast to the last eight years in which hundreds of people died in sectarian attacks.
The period commemorates the martyrdom of Hussein, the grandson of the Prophet Mohammed, who was killed in battle in Karbala in 680 A.D.. His death was one of the events that helped create the schism between Sunnis and Shiites, the two main Muslim religious movements.
Iraqi troops and police were deployed in the streets of Baghdad and Karbala, a holy Shiite city where 2 million Shiite pilgrims from across Iraq converged for the festival over the weekend.
No attacks against Shiite pilgrims were reported in Baghdad and Karbala in the last several days, police officials in both cities told CNN.
Abut 30,000 security members from the army and police were on duty in and around Karbala, establishing four rings of security around the holy shrine of Imam Hussein.
More than 200 female security workers were placed at checkpoints to search women passing through, Karbala police said.
Pilgrims chanted, beat their breasts in penance, cut themselves with daggers or swords and whipped themselves in synchronized movements from Saturday through Sunday morning.
Most people in Iraq are Shiites, and the commemoration of Ashura was almost banned under Saddam Hussein, a Sunni. The first public Ashura demonstrations in Karbala after his fall, in 2004, came under attack by Sunni extremists.
In 2005 nearly a thousand Shiite pilgrims died in a stampede over a Baghdad bridge triggered by a rumor that a suicide bomber was among them.
Shiites gained the upper hand politically after Hussein was overthrown by a U.S.-led invasion in 2003. Sunnis felt disenfranchised amid that political backdrop, and many backed insurgent actions against the government.
As a result, Sunni-Shiite violence exploded in the early 2000s. While full-blown sectarian violence had ebbed by the end of the Iraq War, Sunni extremists continued to launch attacks against Shiite pilgrims over the years.