Iraq's interim government says war crime trials of members of the former regime of Saddam Hussein could begin as early as next week. In the meantime, at least two people were killed and as many as 13 wounded early Tuesday when, for the second time in as many days, a suicide car bomber attacked a security checkpoint in Baghdad. And, a group of celebrities, accompanied by the head of the Pentagon, arrived in Baghdad to help boost morale among U.S. troops in Iraq.

The interim prime minister of Iraq, Iyad Allawi, told a gathering of the interim national assembly Tuesday that trials of suspected war criminals could begin in Iraq as early as next week. If so, senior government officials in Iraq say those trials would likely begin with war council members of the former regime of Saddam Hussein. Mr. Allawi did not specify who would be going on trial and it has not been disclosed when Saddam Hussein himself might face trial.

The prime minister also said Iraqi security forces had killed a senior aide to wanted militant Abu Musab al-Zarqawi, and took into custody two other wanted militants. Mr. al-Zarqawi is the most wanted man in Iraq. He is believed to be behind numerous car bombings, kidnappings and killings of hostages.

Mr. Allawi made his comments just hours following a second car bombing in as many days outside the heavily protected Green Zone in central Baghdad.

Twenty-four hours after a suicide bomber struck Monday at an entrance to the Green Zone, another suicide bomber blew himself up near the same location. An Iraqi National Guard recruiting station is also located in the area.

The area is the most heavily protected and fortified section of Baghdad, where several embassies and the offices of the interim government are located. It has become a favorite target of insurgents over the past several months, attacking it with car bombs, mortars and rockets.

Attacks in Baghdad have become more deadly ever since the U.S.-led invasion last month of the city of Falljuah, west of Baghdad. That assault was intended to root out thousands of insurgents. Since then, interim government officials have said the insurgents have spread throughout Iraq.

Military and interim government officials say they expect the insurgency to become more violent as the country prepares for national elections to be held next month.

Meanwhile, Pentagon Joint Chiefs of Staff chairman, General Richard Myers, arrived in Baghdad for a visit intended to boost morale among the troops. He was accompanied by actor Robin Williams, former American National Football League quarterback John Elway and sportscaster Leeann Tweeden.

General Myers said U.S. troop levels in Iraq will rise to 150,000 by the scheduled January 30 elections. He said events on the ground in Iraq would determine whether the troop level would be scaled back afterwards.

Iraqi voters will go to the polls to elect a 275-seat interim national assembly, that will be responsible for writing a new constitution. They will decide late next summer whether to approve that constitution. Elections for a permanent national assembly are expected by the end of next year.