The US-launched war "is an aggression against religion, property, people and honor," he said.

"This is why jihad is a duty."

The speech was read on television by Information Minister Mohammad Said al-Sahhaf, a move which though not unprecedented, fuelled new speculation in Washington and London on the Iraqi leader's fate and whereabouts.

A Downing Street spokesman said: "We can't reach any definitive conclusions, but Saddam's non-appearance does raise questions about the legitimacy of his other broadcasts."

"It is well-known that his messages on television are one of the ways he maintains his grip on power. It does seem very strange that he hasn't appeared at this time," the spokesman said.

US Defense Secretary Donald Rumsfeld said separately: "Nobody knows where Saddam Hussein is, whether he's alive or dead."

Western media have said Saddam may have been killed or wounded in an air strike at the start of the US-British military campaign. The Iraqi leader has since been shown several times on state television, but it is not known if the footage was pre-recorded.

Just hours after the war began with a March 20 strike on Baghdad, the president was seen on state television calling on his people and other Arabs to resist the attack.

He gave another address on March 24 in which he pledged that "victory is near" and warned of "heavy consequences" for the coalition forces.

In the speech read by Sahhaf on Tuesday, Saddam again pledged that Iraq would prevail over the US and British forces.

"Hit them, fight them! They are evil aggressors," said Saddam, in an address for both his people and "the sons of our glorious (Arab) nation."

"Fight them like brethren and sons of yours have done in Umm Qasr, Basra, Nineveh and Nasiriyah," he said, referring to southern areas where coalition troops have met dogged resistance.

"You will be victorious and they will be defeated," Saddam vowed.

"Fight them in every location as you are doing today, and don't give them a chance to catch their breath until they pull out of Muslim land."

Never had religious scholars been "as unanimous as they are today that the aggression carried out by the aggressors against the fortress of faith is an aggression against religion, property, people and honor, an aggression against the land of Islam.

"This is why jihad is a duty in confronting them," Saddam said.

"He who dies in the arena (of jihad) will win eternal heaven and God's blessing."

The Iraqi leader described the US and British forces as "invaders, enemies of God and humanity" whom the Iraqis were facing with their "chests filled with faith and love of God."

SPACE.WIRE