A conference on the creation of an interim assembly for Iraq has gone ahead in Baghdad amid new violence in Najaf and the capital itself.
Delegates from across Iraq are at the talks
The gathering at a venue in the city's high-security green zone continued despite a mortar attack nearby which caused several casualties.
Religious and political leaders are due to elect a 100-member interim council ahead of free elections next year.
The Shia militant leader in Najaf, Moqtada Sadr, is boycotting the event.
Three mortar bombs fell on a bus station near the venue a few hours after the conference opened, killing one person and injuring at least 17, Iraqi officials said.
Stewards screamed at delegates to keep away from windows after the blasts shook the building located in the "green zone" which also houses government headquarters and the US embassy, AFP news agency reports.
However the business of the conference soon resumed.
In other developments:
One US soldier is killed by a roadside bomb blast in northern Baghdad, the US military says
- One Dutch soldier is killed and several wounded overnight in clashes with insurgents at an undisclosed location in southern Iraq, the Dutch military report
Militants claiming to hold an Iranian diplomat hostage in Iraq demand the return of 500 prisoners they say remain in Iran after the 1980-88 war
- Najaf's police chief, Ghaleb al-Jazaeri, orders journalists to leave the city.
'Horizons of dialogue'
The conference's more than 1,300 representatives will engage in debates on politics, security, reconstruction, human rights and judicial law.
Prime Minister Ayad Allawi said in his opening speech that the conference was a "first step... to open up horizons of dialogue".
Mortar attacks occur almost daily in Baghdad
The interim council due to emerge will be tasked with monitoring the interim government and helping pave the way towards the first post-war elections in January.
A small group of people claiming to be Shia from Basra stood up in the conference hall and demanded an end to the fighting.
They were told they would have the chance to have their voices heard over the three days of the conference.
The BBC's Alastair Leithead in Baghdad notes that there has been criticism of the way delegates were chosen, but the United Nations has lent its weight to the process.
Explosions and shooting were reported in the centre of the holy city of Najaf on Sunday as US armour moved through the streets.
Sadr represents a small but potent force among the Shia
The fighting appears to be the first since a truce began on Friday after a week of fierce clashes between Shia gunmen loyal to Mr Sadr and the US-led forces.
Negotiations between Mr Sadr and the Iraqi government broke down on Saturday.
Mr Sadr said democracy could not prevail in Iraq while US forces were besieging Najaf, a city holy to all Muslims and the Shia in particular, and he rejected the conference under way in Baghdad.
"They call it a national conference, although it is not," he said on the Arabic satellite TV network al-Jazeera.
He is believed to be staying at the Imam Ali shrine where his Mehdi Army fighters are prominent among the armed groups which guard the shrine and religious schools.
The BBC's Matthew Price in Baghdad says that every day the stand-off in the city continues, Moqtada Sadr and his men gain more support across the country.