Baghdad residents stayed off the streets today as the government imposed a daytime curfew to try to stop sectarian violence between Sunnis and Shias on the Muslim day of prayer.
In a critical test for the Shia-led government's authority and its for its new, US-trained forces after two days of killings, police and Iraqi troops were out in force in Baghdad, turning back those few motorists unaware of the ban on traffic announced overnight.
Reprisal attacks on minority Sunni mosques and more than 130 deaths following Wednesday's bombing of a Shia shrine have seen the United States and United Nations joining efforts to avert all-out civil war.
Washington and the Shia-led Iraqi government have blamed al-Qaeda's Sunni militants for the destruction of the Golden Mosque in Samarra on Wednesday, saying they are seeking to spark just such a conflict.
A militant grouping led by al-Qaeda has accused Shias of carrying out the bombing to justify attacks on Sunnis.
Residents reported fierce clashes in at least two areas in and around Baghdad overnight, both in areas where sectarian tensions are exacerbated by communities in close proximity.
Gunmen stormed a house and killed two Shia men and a woman in Latifiya, just outside Baghdad, at dawn today despite the curfew. Two children were wounded in the attack.
The streets of the capital were quiet at mid-morning. but residents feared the violence could boil over. A spokesman for radical young Shia cleric Moqtada al-Sadr said his followers planned to march to mosques in his Baghdad stronghold despite the curfew to worship at the weekly midday (9am Irish time) prayers.
In Basra and other cities in the heavily Shia south of Iraq, where the curfew does not apply, weekend activities looked normal and religious leaders said they expected full mosques.
Even if the curfew calms passions on the Muslim holy day, Iraq's government will still have to demonstrate it can control Shia militiamen who have been attacking Sunni targets and setting up their own checkpoints in defiance of the state.
President Bush called for calm and the UN envoy invited all parties to talks on a way out of the gravest crisis Iraq has faced since the US invasion three years ago.
Sunni political leaders pulled out of talks on forming a government from groups elected in a ballot in December.