In this videotape broadcast on Arab language television, members of a group calling itself the Salvation Movement question how Abu Musab al-Zarqawi, blamed for some of Iraq's deadliest terrorist attacks and two beheadings of foreigners, can justify such acts in the name of Islam. In what amounts to the first such threat of its kind, the gunmen on the tape vow to kill him if he does not leave Iraq. U.S. forces have been after the Jordanian as well and have carried out a number of deadly air strikes on targets in Fallujah where they believe his supporters or even Abu Musab al-Zarqawi himself are active.

The threat by one Muslim group to go after another in the name of Islam comes on the same day that another car bomb exploded north of Baghdad, this one where people were gathering to attend funeral services for a previous attack.

As early as Wednesday, Iraq's interim government is expected to announce new security measures to better combat an insurgency that more than 150,000 foreign forces in the country, nearly all of them American, have not yet been able to put down.

Meanwhile, confusion surrounds the status of a Lebanese-American Marine who has been missing in Iraq since last month and who was threatened with execution. In Lebanon, the brother of Corporal Wasef ali Hassoun says the Marine has now been released, but there has been no confirmation of that and a U.S. military spokesman in Baghdad says the Muslim serviceman remains listed as captured.

On Saturday, Islamic websites had reported that he had been beheaded, but later, another group reported the Marine to be in safe hands.

In another development, the New York Times, reports the Central Intelligence Agency did not tell President Bush that relatives of some Iraqi scientists had reported before the war that Iraq was no longer making weapons of mass destruction.