Saddam Hussein has called on foreigners to leave Iraq and threatened attacks in countries with troops occupying his former stronghold, according to a letter he purportedly faxed to an Arabic newspaper on Friday.

"We warn all foreign citizens and all those who came with cowardly occupier...of the need to leave Iraq before the 17th of next June," said the three-page letter, sent to the London-based al-Quds al-Arabi and made available to Reuters.

Abdel-Bari Atwan, the editor of the paper, said the author may have intended to say July 17, a day which would mark the anniversary of Saddam's Baath party coming to power in 1968.

"If this period ends without them leaving, it will be our right for us to take our defence to their countries. As they kill the sons of Iraq, we will respond," said the letter signed 'Saddam Hussein.'

Following a US and British invasion that toppled Saddam on April 9, other countries have sent troops to help with the task of restoring security in Iraq.

The letter singled out Poland and Denmark as nations with troops in Iraq.

Atwan said the handwriting and signature were the same as four other letters attributed to the ousted Iraqi leader and faxed to the paper in the weeks after the war.

Atwan said he had no indication where the letter, dated June 12 and received on Friday, was faxed from. His paper would publish it on Saturday, he added.

The fate of Saddam and his family is unknown. The United States launched its war in Iraq on March 20 with an air strike directed at a meeting believed to be attended by Saddam.

A second air strike in a fashionable section of Baghdad also targeted Saddam but there was no indication he was killed in either attack.

"I would obviously much prefer that we had clear evidence that Saddam is dead or that we had him alive in our custody," Paul Bremer, the US civil administrator in post-war Iraq, told reporters in Washington on Thursday.

"I think it does make a difference because it allows the Baathists to go around in the bazaars and in the villages, which they're doing, saying, 'Saddam is alive, and he's going to come back, and we're going to come back.'"

The US military has launched two big operations west and north of Baghdad this week to try to root out what it says are diehard Saddam loyalists behind a recent spate of attacks on US troops in mainly Sunni Muslim areas.