More than 21 million Shiite Muslims took part in the Arbaeen pilgrimage in Iraq this year, which reached its peak Sunday with attendees displaying their support for Gaza.

Arbaeen, which means forty in Arabic, marks the 40th day of mourning for the martyrdom of Imam Hussein, the grandson of the Prophet Mohammed and a founding figure in Shiite Islam.

It is one of the world's biggest religious gatherings and a major event for Shiites, who are the majority in Iraq and Iran.

Karbala, where Hussein and his brother Abbas are buried in two enormous mausoleums facing each other, is the center of the Shiite world during this time.

Pilgrims freely express their suffering, weeping and wailing in memory of Hussein, who was killed in 680 A.D. during a battle in Karbala with the Umayyad caliph Yazid.

This year, the events have included prominent displays of Palestinian flags by pilgrims, AFP photographers reported, amid the war in Gaza.

"The total number of Arbaeen pilgrims... reached 21,480,525," the institution that manages the Abbas mausoleum and is responsible for the count, said.

Among them were about 3.5 million Iranian pilgrims, according to official figures reported in Tehran.

Source: Agence France-Presse