The unrest followed the release of figures showing that Iraqi deaths from attacks had fallen in June following one of the bloodiest months since Saddam Hussein was toppled in April 2003, although the US death toll was higher.

A senior advisor to Shia spiritual leader Grand Ayatollah Ali al-Sistani, Sheikh Kamaleddin al-Ghuraifi, was shot dead with two others in Baghdad on his way to Friday prayers, the defence ministry and Sistani's office said.

A suicide car bomber also blew himself up near an office of Jaafari's Islamic Dawa Party in western Baghdad, killing one and wounding another, a defence ministry source said.

Other attacks in Baghdad and in and around the restive city of Samarra further north killed 14 police and soldiers and wounded at least seven, police and army sources said.

In June, a total of 430 Iraqis were killed and 933 wounded, according to data provided by the Iraqi ministries of defence, health and the interior.

The toll was down by more than one-third from 672 in May, which witnessed a surge in attacks following the formation of Iraq's first democratically-elected government in half a century under Jaafari.

Civilians accounted for 266 of the dead in June, while 123 policemen and 41 soldiers died in a total of 160 attacks, most of them car bombings. On the insurgent side, 229 were reported killed while 1,521 were detained.

More than 10,000 civilians have been killed since the handover of sovereignty to Iraqis a year ago, according to the independent Iraq Body Count website.

US casualties in June came to 77 dead, Pentagon figures showed, bringing to 1,731 the number of soldiers who have lost their lives since the US-led invasion of March 2003.

US and Iraqi forces have launched a series of sweeping raids against rebels including Operation Lightning in and around Baghdad in late May, an offensive which involves 40,000 members of Iraq's security forces in a bid to root out insurgents in the capital.

Chief US military spokesman Air Force Brigadier General Donald Alston declined to give the precise number of car bombings before and after Operation Lighting took effect.

But, he said "in the 25 days after Al Barq (Operation Lightning) the number was less than half."

Despite Iraqi government calls for support, foreign ministers from the Organisation of the Islamic Conference meeting in Yemen said the group's 57 members insisted on a right of legitimate resistance against occupation.

The OIC statement condemned "all aspects of terrorism" but insisted on "differentiating between terrorism and legitimate resistance against occupation," a reference to around 160,000 US-led troops in Iraq.

In the latest counter-insurgency operation in the restive Al-Anbar province, US and Iraqi forces were "focusing on clearing insurgents and foreign fighters from the city of Hit," a US military statement said, adding that 13 suspects were arrested in house raids.

The offensive followed Operation Spear last week, in which ground troops and air strikes hammered suspected insurgent hideouts further west near the Syrian border.

US-led forces had already battled rebels in the area west of Ramadi in February, but they quickly reorganised and struck elsewhere within the vast and lawless Al-Anbar province.

Both US and Iraqi officials say die-hard Saddam loyalists and militant foreign fighters brought in by the al-Qaeda network are fuelling the insurgency.

In Geneva, Iraq's government called for an international conference to consider a suspension of around 33 billion dollars in outstanding compensation payments it owes for damage caused by the Gulf War, UN officials said.

The body dealing with the payouts, the UN Compensation Commission, completed examination of the last round of claims under a process that began 14 years ago under Saddam.

About 41 billion dollars of the total 52.5 billion dollars in approved compensation is Kuwaiti, UNCC spokesman Joe Sills said.

Meanwhile, the United Nations Population Fund signed an agreement with the Iraqi planning ministry to train Iraqis to conduct a national census in 2007.

The last official census in Iraq was held in 1997 under Saddam and found the country had a population of 23.8 million.