kerbala iraq chant flail mourn imam hussein hundreds thousands shi ite muslims around world gather iraqi city kerbala friday one sacred rituals religious calendar arbain mark culmination 40-day mourn period imam hussein grandson prophet mohammed kill 7th century battle kerbala shi ites believe remain entomb exhaust pilgrims include women carry children march long distance reach shrine many arrive air iran pakistan bahrain land baghdad several days early kerbala 80 km 50 miles south capital cloak black rob wear pilgrims bedeck sea flag saddam hussein sunni ban shi ite gather religious events decades pilgrims gather sacred shi ite cities include kerbala najaf religious duties since u.s.-led invasion topple 2003. gather mar suicide bomb carry sunni militants notably al qaeda islamic state regard iraq majority shi ites infidels group largely defeat u.s.-backed iraqi security force shi ite pilgrims may peace mind year arbain though security remain tight across country group people build camp cook share food others display decorative object banners feature imam hussein word put wall build ritual time sorrow self-reflection mourn shi ites listen recollections hussein family kill theme martyrdom dominate pilgrims gash foreheads swords beat chain hussein death interpret shi ites symbol struggle injustice oppression tent set kerbala provide rest place pilgrims men serve cup free tea others offer free massage arrive foot different cities tailor work religious flag market shi'ites gather iraq 's kerbala mourn rite