A Shi'ite man in front of the Imam Hussein Shrine in the holy city of Karbala, holding the chains with which he will flagellate himself in one of the most recognizable ceremonies of Ashura, one of the holiest days on the Shi'ite calendar (see also RFE/RL video of Afghan Ashura festivities here ).
During Muharram, the first month of the Islamic calendar, which includes Ashura, many Shi'ite pilgrims converge on central Iraq, site of the seventh-century Battle of Karbala that led to the death of the Prophet Muhammad's grandson, Hussein.
Children prepare for Ashura ceremony in Karbala, Iraq. They are wearing the traditional Muslim caps, taqiyah, inscribed for the occasion and waving banners that bear the likeness of Imam Hussein.
Imam Hussein's image is omnipresent at the height of Ashura and throughout the 40 days of mourning that follows. Here, street vendors in downtown Baghdad are selling pennants and other items portraying Hussein, who felt the Umayyad caliphate threatened the imposition of hereditary leadership.
Shirtless Shi'ite youths prepare for the mass self-flagellation ritual in Kabul, Afghanistan, where a majority of Muslims are Sunni. An estimated 10-13 percent of the world's 1.5 billion or so Muslims are Shi'ite.
Ashura ceremonies include passion plays, like this one in Tehran on December 15, where participants reenact the final hours of Imam Hussein and his 72 companions. Iran is one of a small handful of countries with Shi'ite majorities.
Beatific images of Imam Hussein are conspicuous among Shi'a during events surrounding Muharram, including the pilgrimages to the site in modern Iraq of the Battle of Karbala.
Shi'ite men ritually whip themselves with chains in an effort to share the suffering of Hussein, demonstrate piety, and spurn the trappings of the flesh and worldly concerns.
The conspicuousness and passion of Ashura serve to accentuate the distinctiveness of Shi'ite Islam from its Sunni cousin. The 10th day of Muharram is also revered by Sunnis, but rather as the anniversary of the victory of the Prophet Moses and his people over Egyptian oppressors.
A "fountain of blood" during Ashura celebrations at a shrine in the Iranian holy city of Qom, a major hub of Shi'ite scholarship.
The uniqueness of the Ashura rituals to Shi'ite Islam has led to the targeting of such gatherings by individuals seeking to sharpen the Shi'ite-Sunni divide. This suicide bombing in the southern Pakistani port city of Karachi in December 2009 killed more than a dozen people and injured many others.
A Pakistani security officer guards praying Shi'a during Ashura ceremonies in Hyderabad.
A Shi'ite woman mourns during an Ashura procession at the Taza Pir Mosque in Baku, Azerbaijan, in 2009.
Thousands of Shi'ite women perform the Arba'in mourning ritual outside the Imam Abbas Shrine in Karbala, Iraq.
Arba'in marks the end of the 40-day period of Shi'ite mourning that begins on Ashura. On Arba'in, Shi'a converge on Karbala and central Iraq, as this scene from outside Baghdad's Imam Musa Mosque in February 2009 shows.