Updated

Muslims across the Islamic world took part Monday in the religious festival of Ashoura, marked by fasting and bloody mourning rituals for the death of Prophet Mohammad's grandson Imam Hussein.

Speaking at a mosque in the capital, Afghan President Hamid Karzai spoke of the significance of Ashoura: "This day teaches us about resistance and to fight for our rights, even if we are weak and not armed with weapons."

Ashoura, or 10th day of the lunar month of Muharram, is marked by Muslims as a whole with a day of fasting that commemorates the day Noah left the Ark, and the day that Moses was saved from the Egyptians by God.

For Shiites, Ashoura is a solemn day of mourning the martyrdom of Imam Hussein in 680 AD at Karbala in modern-day Iraq. Shiites, who make up 15 percent of the world's Muslims, believed Hussein was the rightful successor to Muhammad.

Following Muhammad's death, a schism developed within the community about who was to succeed him in leadership of the Muslim nation. This was the beginning of the historical split between Sunnis and Shiites.

In Kabul, Afghanistan, hundreds of Shiites mourned the martyrdom of Imam Hussein by slapping their bodies with sharpened chains. A march was led by a horse meant to symbolize Hussein's steed and decorated with religious motifs.

In Karbala, hundreds of pilgrims, most wearing black shirts in a show of mourning, packed the inside of the golden-domed Shrine of Imam Hussein, praying fervently, beating their chests and wailing for the loss of their martyr.

Karbala police said more than 2 million pilgrims had gathered under a dust-filled orange sky caused by a sandstorm that blanketed much of central and southern Iraq.

In Baghdad, crowds dressed in black for mourning and holding aloft green banners bearing the name Hussein filled a broad central street.

Marking Ashoura was severely restricted by Saddam Hussein's Sunni-dominated secular state. Those who made the pilgrimage to Karbala or performed public rituals were often arrested and many faced torture and death. Repression was eased in later years.

The festival, which lasts more than a week, will rise to a crescendo on Tuesday, the actual Ashoura, or 10th day of Muharram.