Al-Jazeera airs tape claiming Saddam leads attacks
The voice urged Iraqis to help the resistance against the US-led occupation.
"Oh brothers and sisters, I relay to you good news: Jihad (holy war) cells and brigades have been formed," the speaker on the audiotape said, addressing the Iraqi people.
The CIA is reviewing the tape, but has not verified that it was the ousted Iraqi leader, a US intelligence official said. An analysis could take several days.
There was no immediate way to verify the tape's authenticity. Reporters and others who have heard Saddam speak many times before said the voice sounded like Saddam. The voice contained characteristics similar to Saddam's style of speech, particularly his typically slow and drawn out pronunciation. He also maintained his usual defiant, yet calm, demeanour.
With US forces targeted daily by ambushes and sniper attacks in and around Baghdad, the United States has put a $25 million bounty on Saddam's head as well as a $15 million reward for each of his sons, Odai and Qusai.
US officials say the mystery over Saddam's whereabouts fuels anti-US attacks by loyalists but insist the resistance is not centrally organised.
In the audiotape, the speaker gives the date of taping as June 14 and says: "People have been asking why they haven't heard the voice of Saddam Hussein. We face a lot of trouble in getting our voice to you even though we have been trying."
The speaker defends the quick fall of Saddam's regime during the US-led invasion in March and April, saying it was a necessary retreat, and urges Iraqis to help insurgents.
"No to surrender and no to cooperation" with the Americans, he said. "I call upon you to protect these heroic fighters and not give the invaders any information about them or their whereabouts.
"There is resistance and I know you are hearing about this. Not a day passes without them (suffering) losses in our great land thanks to our great mujahedeen. The coming days will, God willing, be days of hardship and trouble for the infidel invaders," the speaker said.
The last reported sighting of Saddam was on April 9, a day before the capital fell, in northeast Baghdad. He was the target of at least two major US air strikes, but there was never any proof either were successful.
