"They will try to remain on the sidelines to suffer the least possible damage, until they are certain that the Iraqi regime's repressive machine has been annihilated," an official from the Supreme Assembly of the Islamic Revolution in Iraq (SAIRI) told AFP.

"When this point is reached, they will start organising themselves," Mohsen Hakim said.

Troops of the US-British coalition were nearing Baghdad Friday and controlled much of Saddam International Airport, 20 kilometres (12 miles) from the city centre.

The Pentagon is betting on the collaboration of the Shiite half of the population in the five-million-strong capital, persecuted by the regime of Saddam Hussein.

"Given Shiites are half the population ... you probably have people ready to help out, you have to be patient," Chairman of the Joint Chiefs of Staff General Richard Myers said.

Saddam and most of his regime are from Iraq's Sunni minority.

At the beginning of the war two weeks ago, SAIRI chief Mohammad Baqer Hakin urged Shiites to remain neutral, blaming both the Americans and Saddam for the war.

The coalition has decided not to include the Shiites in its war effort, unlike the Kurds in the north who are advancing on government-controlled cities backed by US and British aircraft.

However in Beirut, Sheikh Hussein Fadlallah, spiritual leader of Lebanon's fundamentalist Shiites, called on all Muslims to resist the coalition forces in their drive to Baghdad.

"We urge US-British forces not to attack holy sites (in Najaf and Karbala) and we call on Muslims and free men around the world to resist the invaders," he told worshippers after Friday prayers in Beirut.

"The enemy plans to reduce the Umma (the Muslim nation) to impotence to impose on it new regimes serving them and replace a dictator (Saddam) by a tyrant of their own," Sheikh Fadlallah warned.

On Friday, Saddam was quoted by his information minister, Mohammad Said al-Sahhaf, as calling on all Baghdadis to resist advancing US-British forces, saying, "We believe in God and we count on him for a victory which he has promised to believers, and that is our right."

Akbar Hashemi Rafsanjani, a former Iranian president and still a key figure in Iran, meanwhile warned of the fury any damage inflicted by coalition forces on holy sites could trigger.

"I am warning the White House and Britain: let not your vanity or your fervour harm Shiite Islam's holy sites because Shiites will never forgive you and they, as well as God, will avenge it in due time," he said.

Rafsanjani, who heads the Expediency Council that arbitrates disputes between branches of the regime, temporarily set Iran's historical differences with Iraq aside and argued that the United States was a greater common enemy.

"The United States has become an ignominious monster and the most abhorred figure in the world," he charged. "The American danger is greater than Saddam and his Baath party."

The central Iraqi cities of Najaf and Kerbala, which have been the scene of intense fighting between coalition troops and Iraqi forces, are the holiest in Shiite Islam after Mecca and Medina.

The Shiite religious leader in Najaf, Grand Ayatollah Mirza Ali Sistani, had denied a US military report that he had issued a fatwa (religious decree) calling on the populace not to impede coalition military forces, Arab news channel Al-Jazeera reported Friday.

On the contrary, Iraqi television said Sistani and four other top Shiite clerics at Najaf had called on Iraqis of all beliefs and ethnic groups to unite in the defence of their country against "the enemies of God and humanity."

The television showed an aged cleric, who was not identified, reading the fatwa to this effect.

SPACE.WIRE