DOHA, Qatar (AP) -- The purported voice of Osama bin Laden tells his followers to help Saddam Hussein fight Americans even though his government is of ''infidels,'' words U.S. officials said showed the Iraqi leader's ties to the al-Qaida terror network.

The voice on the tape aired Tuesday by the Al-Jazeera satellite television station throughout the Arab world urged Iraqis to stage suicide attacks and lure American troops into bloody urban battles to inflict ''big casualties.''

U.S. officials said they believe the voice on the tape is that of the elusive bin Laden. Secretary of State Colin Powell said the comments, broadcast on the first day of the major Islamic holiday Eid al-Adha, bolstered U.S. allegations that Iraq is harboring al-Qaida operatives.

''This nexus between terrorists and states that are developing weapons of mass destruction can no longer be looked away from and ignored,'' Powell told the Senate Budget Committee.

Some Middle East experts have questioned ties between bin Laden's Islamic extremists and Saddam's government, which nominally adheres to a Pan-Arabic socialistic doctrine called Baathism.

In the tape, the speaker said Iraq was governed by socialist ''infidels,'' including Saddam. He said that it was acceptable for Muslims to fight on behalf of Iraqi ''socialists'' because ''in these circumstances'' their interests ''intersect in fighting against the Crusaders,'' or Christians.

There was no immediate comment from the Iraqi government, which has repeatedly denied links to al-Qaida. The tape has not been reported on Iraqi media and most Iraqis do not have satellite dishes.

Some U.S. analysts wondered at bin Laden's motives for issuing a statement supporting Iraq, given many countries' skepticism of U.S. allegations of Iraqi-al-Qaida links. Others worried the recording would inflame Muslims against U.S. troops in the Persian Gulf region.

The tape was broadcast as U.S. officials were warning of imminent terror attacks in the United States or in the Persian Gulf, where more than 113,000 U.S. troops are massing for a possible attack on Iraq.

On the tape, the speaker urged Iraqis to profit from the lessons learned by al-Qaida fighters in the war against the Americans and their allies in Afghanistan.