Shiites in their hundreds of thousands were descending on Iraq's holy city of Karbala on Wednesday ahead of the climax of Ashura ceremonies, surrounded by heavy security over fears of attacks.
Black flags, representing the sadness of Shiites during Ashura, and pictures of the revered Imams Hussein and Abbas, both of whom are buried in Karbala, were seen throughout the city, while violence targeting pilgrims in Iraq has claimed the lives of 10 people in the past few days.
Some 28,000 soldiers and police were securing the city, with a further 7,000 available if needed for the two million followers expected to visit Karbala, including around 100,000 foreigners.
Provincial authorities deployed dozens of mobile medical units across Karbala, 100 kilometres (60 miles) south of Baghdad, for pilgrims, many of whom had travelled by foot from across Iraq.
The authorities were also testing the quality of water and food being handed out.
"I challenge the terrorists who do not want the ceremonies to continue ... I don't know how they consider themselves Muslims," said Hussein Kadhim, a pilgrim from the outskirts of Karbala city.
"We will continue with our ceremonies even if they attack us, even if they kill us."
Visible signs of the heavy security were evident throughout, as private vehicles were banned from entering Karbala and all pilgrims entering the city were searched, with bomb-detection devices and explosives-sniffing dogs being used in vehicular searches.
Six security perimeters have been established around the city, with a particular focus on entrances to Karbala and its old city, close to Imam Hussein's shrine.
Ashura has in previous years been a target for Sunni Arab extremists, who see the 10-day ceremonies as symbolically highlighting the split between Islam's two main communities.
Suicide attacks and roadside bombs in Baghdad and the central province of Diyala since the first day of Ashura, which means tenth in Arabic, on December 8 have claimed the lives of 10 pilgrims.
The deadliest Ashura attacks were in March 2004, when near-simultaneous bombings at a Shiite mosque in Baghdad and in Karbala killed more than 170 people.
The 10-day rituals, which climax on Friday, 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.
Ceremonies begin with devotees drenched in blood after ritually slicing their scalps and flaying themselves with chains attached to sticks during processions, symbolically showing their guilt and remorse for not defending Hussein.
While thousands of pilgrims visit Karbala and other major Shiite shrines in Samarra, Najaf and Baghdad, every day -- many from Iran and other countries with large Shiite populations -- the number peaks during Ashura.
The massive influx means Karbala's 320 hotels have been filled, and local families are now opening their homes to travellers.
Shiites 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.