Updated

The CIA says an audio recording purportedly of Saddam Hussein denying involvement in last week's bombing in Najaf is probably authentic.

A CIA official said the poor quality of the audio message, aired Monday on the Arabic al-Jazeera television network, prevents technical analysts from being certain.

In the message, the voice urged the Iraqi people not to believe those who blamed the ousted dictator and his followers for Friday's attack on the Imam Ali Shrine (search) in Najaf that killed Ayatollah Mohammad Baqir al-Hakim (search) and scores of others.

"Many of you may have heard the snakes hissing, the servants of the invaders, occupiers, infidels, and how they have managed to accuse the followers of Saddam Hussein of responsibility for the attack on al-Hakim without any evidence," said the tape.

"They rushed to accuse before investigating," the voice said.

Quoting the Quran, the voice said:

"Ye believers, if a corrupt person brought you news, check it well before accusing arbitrarily. Otherwise, you will regret your accusation."

Al-Hakim was a longtime opponent of Saddam and spent more than two decades in exile in Iran, returning to Iraq only in May. Crowds of mourners have accused Saddam loyalists of killing the cleric. His funeral was Tuesday.

U.S. officials say it is too soon to know who bombed the mosque. Nor have they unraveled the Jordanian Embassy bombing on Aug. 7 or the U.N. headquarters attack 12 days later.

On the audio message, the speaker made no mention of those two attacks.

Iraqi police officials leading the mosque bombing investigation have said they believe Al Qaeda-linked Islamic militants were behind the attack. The FBI said Sunday it would help investigate the bombing after receiving a request from local officials.