Another Iraq Suicide Blast Kills 53 Shiites in Basra Victims were marking a holy day By John Johnson, Newser Staff Posted Jan 14, 2012 6:27 AM CST 4 comments Comments An Iraqi soldier mans a checkpoint in Baghdad Saturday to secure the return of Shiite Muslim pilgrims from the city of Karbala after the feast of Arbain. (Getty Images) (Newser) – Iraq's Sunni-Shiite tensions worsened yet again today when a suicide bomber killed at least 53 Shiite pilgrims marking a holy day, reports Reuters. The bomber, dressed as a police officer, struck at a checkpoint in Basra. No claims of responsibility yet, but it bears the hallmarks of Sunni-dominated al-Qaeda, which is trying to capitalize on the sectarian chaos, notes the New York Times. It also comes in the shadow of Sunni-Shiite tensions at the political level, notably playing out in the feud between Shiite Prime Minister Nouri al-Maliki and his Sunni vice president. “The main goal of these attacks is igniting the sectarian violence,” says a member of Iraq's parliament from Basra. "But I don’t think the sectarian violence will return because people know what the insurgents are trying to do."