Gunmen shot and killed three Sunni Arab members of the committee drafting Iraq's new constitution as they left a Baghdad restaurant Tuesday, police sources said.

The killings in the Karrada district of central Baghdad are a crushing blow to hopes that a nascent political process could undermine Iraq's insurgency.

The Sunni Arabs on the committee were seen as central figures in the US-backed strategy of drawing members of the restive minority off the streets and into peaceful politics.

A television cameraman at the city's St Raphael's Hospital saw three bodies being pulled out of a dark blue car that had been sprayed with bullets. Their wounded driver was loaded into the back of a truck.

Police sources named the victims as Sheikh Mujbil al-Sheikh Isa, Aziz Ibrahim and Dhamin Hussein Ileywi.

The 71-strong committee is due to deliver Iraq's new constitution by August 15.

Fifteen Sunni members joined it last month, making it the first nationwide political body to include significant Sunni representation since the new government took power in April.

The other members are mostly Shi'ites and Kurds, elected to parliament in a January vote when most Sunnis stayed home.

Two members of parliament have been assassinated since the elections, but Tuesday's victims were the first members of the constitution-drafting committee to be killed.

Meanwhile, Iraq's prime minister Tuesday criticized delays in trying former leader Saddam Hussein and called on the United States to set a timetable for withdrawing its forces from his country, the state-run Iranian radio reported.

Ibrahim al-Jaafari, who was due to return to Iraq Tuesday at the end of a landmark three-day visit to fellow Shi'ite Muslim-dominated neighbour Iran, described the "prolonging" of Saddam's trial as "unusual."

"While about two years have past since he has arrested, no action has taken about his trial," the radio quoted al-Jaafari as saying during a meeting with Iraqi expatriates in Iran.

In another development, Iraq urged the international community Tuesday to deliver immediately on its aid pledges and warned more delays would further destabilize the troubled country and threaten global security.

The international community has pledged billions of dollars to help rebuild Iraq but only a small amount of that has actually been spent.

Concerns about the sustainability of the post-Saddam Hussein political system, violence and widespread corruption have led donors to be cautious about implementing their pledges.

"Unless we move fast and effectively in the next few months we will have very serious problems on our hands," Planning Minister Barham Salih said.

"Failure is not an option because it will have dire consequences for the Iraqi people and for the region and for world security."

Salih was speaking on the second day of a meeting of 60 countries and international organizations, to follow up on conferences in Madrid and Tokyo over the last two years at which they pledged US$14 billion.

Source: China Daily