An alleged spokesman for the al-Qaeda network has broadcast a message warning of more anti-American attacks, but denying any role in last month's devastating bombing in the Iraqi holy city of Najaf.
The Najaf bombing has enraged Iraqi Shias
The 29 August car bomb blast in Najaf, which killed top Shia Muslim cleric Mohammed Baqr al-Hakim and at least 80 others, has been blamed by some Iraqi Shias on al-Qaeda.
The audiotape message was broadcast on Sunday by Dubai-based Al-Arabiya satellite television, which identified the speaker as Abd al-Rahman al-Najdi.
He warned that "there will be new operations inside and outside [Afghanistan] that will make the United States forget the 11 September  events".
Mr Najdi said the Taleban leader, Mullah Muhammad Omar, and al-Qaeda leader Osama Bin Laden were "leading and directing the battles by themselves from inside Afghanistan".
Turning to the Najaf attack, he said: "We strongly deny any al-Qaeda role in the bombing that killed Mohammed Baqr al-Hakim, violated the sanctity of one of the houses of God and killed innocent people.
"We do not have any such objective. Our main objective is to fight and kill the Americans wherever they are on the globe and to drive them out of Palestine, the Arabian Peninsula, and ancient Iraq."
He blamed the killing of Ayatollah Hakim on "the Americans and Jews", who wanted to "get rid of him, for they knew about his loyalty to Iran".
Last month, the US State Department denounced Al-Arabiya as "irresponsible" for showing masked men threatening to kill members of the US-appointed Iraq Governing Council.
The pan-Arab channel began broadcasting in March this year.
The BBC's Julia Wheeler in Dubai says the latest message comes at a poignant time, just days before the second anniversary of the 11 September attacks on New York and Washington.
She says it will remind many people in the Middle East that the US is still trying to capture Bin Laden and neutralise the threat from al-Qaeda.