Media reports were false8217;

But in Washington the US State Department gave its strongest backing yet to the reports of unrest saying they came from 8220;sources which have proven to be reliable in the past8221;.

And in Teheran, Iraqi security guards fired shots in the air and four people were injured as some 1,000 opponents of Saddam8217;s regime attacked Iraq8217;s embassy, opposition sources said.

In Nassiriya, several residents interviewed denied any trouble had taken place in the city following the assassination on Friday of Grand Ayatollah Mohammad Sadek al-Sadrand two of his sons.

Traffic policemen were the only security presence spotted on a tour around Nassiriya, 300 km from the capital. Shops were open and traffic flowed as normal. 8220;What the media reported was all false,8221; provincial governor General Ahmad Abdallah Saleh told reporters.

Journalists saw no sign of bombardment, despite Opposition reports that the Army used heavy artillery to shell Nassiriya after losing control of parts of the city of one million people. The walls of Nassiriya were plastered with portraits of Saddam and graffiti blasting the US. No broken windows, bullet holes or spent cartridges were visible.

A Shiite Opposition group based in Iran, the Supreme Council for Islamic Revolution in Iraq SCIRI, said that Army shelling had killed at least 18 people in Nassiriya. Iraqi sources in Amman said that security forces had 8220;violently suppressed8221; any unrest, although not before the troubles spread to the western Sunni town of Ramadi on Sunday.

Armoured vehicles patrolled the streetsof many of Iraq8217;s main cities on Monday, the third straight day of clashes which left at least 100 dead in Baghdad alone, according to witnesses and other Iraqi sources.But the authorities dismissed all reports of violent protests in Shiite suburbs of Baghdad and mainly Shiite southern cities, and the information ministry organised a tour in an effort to prove its case.

According to a foreign diplomat based in Baghdad, the news of Sadr8217;s assassination brought people into the streets of the vast suburb of Saddam City on Saturday. 8220;The security forces soon brought the demonstrators under control and calm was restored,8221; the diplomat said.

The Opposition blamed Sadr8217;s killing on Baghdad, but the Government insisted the murder was the work of a criminal and a youth television station run by President Saddam Hussein8217;s eldest son Uday carried a picture of a man the police wished to question.

Foreign Minister Mohammad Said al-Sahhaf sparked outrage in Washington by suggesting that US was behind Sadr8217;skilling. 8220;The US announced that they have drawn up a plan to overthrow the Iraqi regime and that they have allocated 97 million to finance an insurrection in Iraq. That is why I don8217;t rule out their involvement in the killing,8221; Sahhaf told reporters in Beirut.

8220;That is a baseless and shocking and completely erroneous accusation,8221; said State Department spokesman James Foley, adding that Baghdad remained the prime suspect in Sadr8217;s murder.

8220;It8217;s clear this is the fourth religious cleric who has been assassinated in the last year,8221; he said. 8220;This is an esteemed religious figure who has been visited by and threatened by Saddam8217;s security forces.8221;The human rights organisation Amnesty International said it feared 8220;other Shiite leaders in the country may be at risk8221; and called on Baghdad to 8220;take immediate steps to ensure their safety8221;.