A suicide car bomber killed at least 28 people and wounded 62 on Saturday in the main market of oil-rich Basra, Iraq's second largest city.
The explosion occurred in the late afternoon when a large number of people were in the square, Captain Mushtaq Kadhim of the Basra police said.
The suicide attacker blew himself in the late afternoon when many people were shopping. The blast left pools of blood around the square drenched in blood set several vehicles on fire.
It wasn't known who staged the attack, but Basra has seen growing violence and unrest recently, leading Prime Minister Nouri al-Maliki last week to declare a month-long state of emergency in the mainly Shiite city.
"The size of the security power in this province as far as I know should be sufficient to maintain full control of the security situation, but it seems that these forces are useless with the deteriorating of the security situation in this town," he told about 700 tribal sheiks, religious leaders, officials, army officers and other residents on Wednesday.
The attack came one day after Jordanian-born terrorist mastermind called on Iraq's Sunni Arabs to kill Shiites. His al-Qaida in Iraq has claimed responsibility for some of the most horrific attacks in Iraq, including bombings that have killed more than 100 people.
In other recent developments: A Russian Embassy official in Baghdad said Saturday that one diplomat was killed and four diplomatic employees were abducted in the Iraqi capital. Police in Baghdad said witnesses at the scene told them that gunmen opened fire on a car that belonged to the Russians in west Baghdad's upscale Mansour district. A military investigation into allegations that U.S. troops intentionally killed Iraqi civilians in a March raid in Ishaqi, a village north of Baghdad, has cleared the troops of misconduct, the military said Friday. The leader of al Qaeda in Iraq urged Sunnis to confront Shiites and ignore calls for reconciliation in a new audiotape posted on the Web on Friday, saying Shiite militias are killing and raping the Sunni Arab minority. The tape was a four-hour sermon by Abu Musab al-Zarqawi against Shiites, denouncing their top cleric Grand Ayatollah Ali al-Sistani as an "atheist" and saying the community had collaborated with invaders throughout Iraq's history. The Pentagon has released the name of the soldier who was killed by the bomb that also killed CBS crew members James Brolan and Paul Douglas and wounded CBS correspondent Kimberly Dozier. Army Capt. James Funkhouser, 35, had been in Iraq only a few months. He leaves behind a wife, Jennifer, and two daughters, Caitlyn and Allison. A military jury on Thursday convicted an Army dog handler of using his animal to torment a prisoner at Abu Ghraib. Sgt. Santos A. Cardona is the 11th soldier convicted of crimes stemming from the abuse of inmates at the prison in late 2003 and early 2004. The U.S. military ordered coalition troops in Iraq on Thursday to undergo special training in ethics and "the values that separate us from our enemies" in the wake of allegations that Marines killed two dozen unarmed civilians in Haditha. The order came as Iraq's government launched its own investigation of the deaths last November in the western town as well as other incidents involving U.S. troops.