He also urged Iraqis not to join the Awakening Councils which are predominantly Sunni tribal police funded by the US military to fight al-Qaeda and reduce violence.

"I advise those who follow the path of temptation should wash out this disgrace by repentance," he said in the 56-minute recording posted on the internet on Saturday.

US progress

"This participation [in the Awakening Councils] is a great apostasy and sedition that will lead them to Hell."

The release of the recording comes as the US and the Iraqi interior ministry claim they have the al-Qaeda organisation in Iraq on the run.

Several hours before the tape was issued, General David Petraeus, the most senior US commander in Iraq, said al-Qaeda was becoming increasingly fearful over losing the support of Sunnis and had begun targeting the leaders of the tribal councils who have switched allegiances to the US.

Bin Laden also criticised the Saudi government for supporting US policies in Iraq.

"The government of Riyadh is still playing its wicked roles," he said.

The recording was posted on the website where al-Qaeda's media arm, al-Sahab, issues the group's messages.

A US counter-terrorism official said Washington was aware of the recording and was looking into it.

"There has never been a fake bin Laden tape, so there really wouldn't be any reason going in to believe it would be anything other than authentic," the official said.

Palestine threat

The tape was the latest message from al-Qaeda leaders trying to patch up divisions among groups in Iraq and rally Sunnis behind al-Qaeda.

On December 16 bin Laden's deputy, Ayman al-Zawahiri, branded those who work with the anti-Qaeda tribal councils as traitors and called for Sunnis to purge anyone co-operating with the Americans.

Also in Saturday's tape, bin Laden promised to widen al-Qaeda's fight to include Israel, stepping up the organisation's attempts to use the Israeli-Arab conflict to rally supporters.

"I would like to assure our people in Palestine that we will expand our jihad there," bin Laden said.

Bin Laden and other al-Qaeda leaders frequently vow to liberate Jerusalem and Palestine in their messages, but the latest comments were more direct.

Israel has warned of growing al-Qaeda activity in the occupied Palestinian territory, but the network is not believed to have taken a strong direct role there so far.

"We will not recognise even one inch for Jews in the land of Palestine as other Muslim leaders have," bin Laden said.

The tape did not refer to the assassination of Benazir Bhutto in Pakistan on Thursday.