KERBALA, Iraq - Shi'ite Muslims gathered at shrines and mosques across Iraq on Tuesday for the Ashoura religious ritual as Iraqi security forces were on alert for possible attacks that have inflicted mass casualties during past pilgrimages.The presence of ultra-hardline Islamic state militants in the country who swept through the north raises the possibility of wider bloodshed this year as crowds swell into the millions.Islamic State, seen as more ruthless than its predecessor in Iraq, al-Qaida, believes Shi'ites are infidels who deserve to be killed and the group has claimed responsibility for numerous suicide bombings against members of the majority sect.Security for the event has been tight since suspected al-Qaida suicide bombers and mortar attacks killed 171 people during Ashoura - an event that defines Shi'ism and its rift with Sunni Islam - in Kerbala and Baghdad in 2004.Shi'ites are commemorating the slaying of Prophet Mohammad's grandson Hussein at the battle of Kerbala in AD 680.
