Many of the dead and the 90 wounded in Hillah, south of Baghdad, had arrived for the funeral of a man killed in an earlier blast. Others had gathered to pray on the first day of the Muslim holy month of Ramadan.
The explosion at the Husseiniyat Ibn al-Nama mosque ripped through strings of light-bulbs and green and crimson flags hung around the entrance to celebrate the start of holy month. The mosque's front was destroyed and shops and parked cars near by suffered severe damage.
The blast was second major bomb attack in a week in Hillah. The town in southern Iraq, heartland of the Shia majority, has suffered badly at the hands of the insurgents. The Sunni extremist group al-Qai'da in Iraq, led by the Jordanian-born militant Abu Musab al-Zarqawi, has called for an " all-out offensive" against Shias during Ramadan.
The violence in Hillah unfolded as Shia and Kurdish members of the Iraqi National Assembly agreed to reverse the change of rules over the impending referendum that had led to condemnation from the United Nations and threats of a boycott from Sunni community leaders.
The change ofprocedures for the referendum on the new constitution would have made it virtually impossible for Sunnis, who oppose the document because of its proposed federal structure for Iraq, to reject it.
The American government, wary of further alienating the Sunni minority, said it welcomed the reversal by the majority Kurdish and Shia members of the Assembly. Scott McClellan, President George Bush's spokesman in the White House, said: "They should encourage broader political participation, and the vote [to rescind the change] is positive."
Said al-Zubaidi, a Sunni member of the National Assembly stressed, however, that the Kurds and Shias have changed their minds thanks not to the US but to the UN. "What happened on Sunday was a big mistake. No one asked us about it. If it had not been for the United Nations, nothing would have changed."
The bomb in Hillah was detonated on the pavement next to the city centre mosque at 6pm, just as hundreds of men gathered there. "While I was praying, I heard a huge blast and realised parts of the mosque were crumbling over my head," said Asaad Jassem, 35, a survivor who had come for the funeral of a restaurant owner killed in a blast on Monday.
"Some parts of the mosque's ceiling fell on to worshippers, I saw people on the ground bleeding."
Haj Mohammed Abdullah, 45, a shopkeeper, said: "We heard an explosion and then I fainted. I woke up when policemen splashed water over my face, and I saw all the damage, the martyrs and the wounded. How could they do this?" The attack came five days after a car bomb exploded in a crowded market, killing 10 people, including three women and two children.
A day earlier, a string of car bombs hit in Balad, a Shia town north of Baghdad, killing 100 people.
Meanwhile thousands of US troops are engaged in two major offensives in western Iraq. The Sunni politicians Saleh al-Mutlak and Hussein al-Falluji said they were planning to call for another voting boycott if they did not stop. "If this continues for another three or four days, we will announce a boycott of the referendum," said Mr Mutlak.Reuse content