Shia stone-throwers clashed with troops in the British-administered port city of Basra seeking to evict a radical Shia group, Tha'r Allah - God's Revenge - from a former government building. British troops in riot gear were reported to have opened fire. News agencies said two soldiers and four Iraqis were wounded.
The Shia unrest followed protests in central Baghdad. A thousand black-shirted followers of young Shia firebrand Muqtada Sadr marched through central Baghdad burning American flags after US forces padlocked the door of their newspaper, al Hawza, saying it had been banned for two months for inciting violence.
"If the coalition forces are going to keep on presenting us with such messages . . . they can just dream about any sort of end to terrorism," a statement from the newspaper said.
The unrest followed a poster campaign and petition drive by supporters of Ayatollah Ali Sistani, the Shia's reclusive but paramount religious authority, who is seeking to overturn Iraq's temporary constitution, agreed this month. The elderly cleric's face now adorns posters plastered across the country denouncing the document. Signed by Mr Bremer and his appointees in the Governing Council, the temporary constitution includes a bill of rights and was hailed as the most progressive in the region.
But Mr Sistani fears the Governing Council has enacted a permanent constitution by the back-door.
In addition to the poster campaign, last Friday imams at thousands of Shia mosques across central and southern Iraq began distributing a petition addressed to the United Nations and Mr Bremer, demanding the law be revoked.
"It is illegal because the administrators who have drafted the law lack legitimacy among ordinary Iraqis," says the petition.
Shia officials at Baghdad's Baratha mosque, who represents Mr Sistani in Baghdad, said tens of thousands had signed the petition.
Underlying the protest is Shia trepidation that Iraq's occupying authorities may be seeking to dilute the majority rule that Shias feel is their democratic birthright. Among Baghdad political classes, there is growing talk that Mr Bremer could hand over power to a Shia prime minister and a Sunni president.
Mr Sistani's representatives have said that if the law is not reversed their ayatollah will boycott talks with the United Nations, who arrived in Iraq this week to help oversee the handover from direct rule by the occupation authorities. Previous objections by Mr Sistani have already twice scuppered Mr Bremer's plans for political transition.
The Shia clerics have concentrated their vitriol on Article 61 of the temporary constitution which provides for two-thirds of voters in any three of Iraq's eighteen provinces to veto a future constitution. The clause was inserted by Iraq's Kurdish minority, fearful that the Arab majority would annul their current autonomy.
