A suicide bomber detonated his explosive vest yesterday in a market in the ancient Iraqi city of Najaf, killing at least 33 people a short distance from Shiite Islam's holiest shrine.
The blast was triggered at the entrance to a market in the old city, 150m from the Imam Ali mausoleum and close to the offices of Iraq's most revered Shiite cleric, Grand Ayatollah Ali al-Sistani, police said.
"The total casualties are 33 killed and 94 wounded, including four Iranian visitors. One of them is in serious condition." said Munther al-Athari, head of the Najaf health directorate.
The attack came as the health ministry said the Baghdad morgue had handled 1,850 corpses last month, most of them murder victims.
It was the latest in a series of bombings and shooting attacks that have poisoned relations between Iraq's majority Shiite community and the once-dominant minority Sunnis.
US generals warned last week that sectarian bloodshed could push Iraq into civil war, despite attempts by the country's unity government to restore order and promote a national reconciliation plan.
"We call upon everyone to stop these attacks that target civilians, the aim of which is to create sedition and internal strife," said Aziz Zein al-Ali, a spokesman for the Supreme Council for Islamic Revolution in Iraq (SCIRI).
SCIRI is a powerful Shiite movement and part of the ruling coalition.
"We do not accuse any particular party but believe that such an act was carried out by Saddamists and takfiris [Sunni extremists] who do not want stability in this country," the spokesman charged.
Imam Ali was both cousin and son-in-law to the Prophet Mo-hammed and Shiites regard him as the prophet's chosen successor to lead the Muslim world. He was murdered in the year 661.
His tomb in Najaf is a place of veneration and pilgrimage for Shiites, who form a minority among Muslims worldwide but are the largest religious community in Iraq and Iran.
After the blast, police swarmed into the old city and shut it down. No cars were allowed to enter, shops were closed and crowds dispersed.
There was no word from the authorities as to who might be behind the attack, but suspicion will fall on extremists from Iraq's Sunni Arab minority.
This in turn could feed the spiral of tit-for-tat revenge killings between rival Sunni and Shiite death squads that has claimed thousands of lives.
Iraqi and US forces are determined to put a halt to the violence, which is focused on Baghdad, and have deployed more than 60,000 police and soldiers in the capital.