The Iraqi Bar Association and attorneys for ousted president Saddam Hussein ended their boycott Wednesday of the former leader's trial and are expected to participate in a court session next week, Iraqi and U.S. officials said.

Hussein's attorneys had suspended participation in the process earlier this month, fearing for their safety. Most of the defense team fled the country after two colleagues were shot to death and another was wounded following the first trial session on Oct. 19.

A U.S. official close to the Iraqi Special Tribunal hearing the Hussein trial said authorities had offered unspecified options in which the defenders could participate without jeopardizing their safety.

Officials for the Iraqi Bar Association said U.S. Embassy officials had met with them, heard their demands and promised an independent investigation into the killings of the lawyers. By refusing to participate, the association could have blocked the use of its members as replacements for defense attorneys.

"We have this condition," said Kamal Hamdoun, chairman of the Iraqi Bar Association, discussing the demand for a full investigation. "It's been met, therefore we will continue working with the tribunal."

Hussein and seven co-defendants, charged with crimes against humanity, are scheduled to appear in court Monday in the second session of the trial. Officials said the court planned to hear witness testimony for the first time in public. Details about those testifying were not provided. A U.S. official said, however, that the tribunal had arranged a witness protection plan and that it would be "up to the witnesses whether they show their faces and reveal their identities or not."

Meanwhile, officials said U.S. and Iraqi troops launched military operations in western Iraq, centered in Tameem, south of Ramadi.

"Tameem is a neighborhood where loyalists and sympathizers with Saddam Hussein live," said Muhammed Dulaimi, a government security adviser. "This operation aims to rout the insurgents, Iraqi and foreign, out of the town."

In Baghdad, gunmen wearing Iraqi army uniforms killed Khadim Sarhid Hemaiyem, a Sunni tribal leader, his three sons and his son-in-law at their home Wednesday, according to the Association of Muslim Scholars, a Sunni organization.

Also in the capital, an American soldier from Task Force Baghdad died of a gunshot wound Wednesday, the U.S. military said. At least 2,108 U.S. servicemen have been killed since the start of the Iraq war, according to the Pentagon.

Sen. Joseph I. Lieberman (D-Conn.), a member of the Armed Forces Committee, spoke out against an early U.S. troop withdrawal during a visit to Baghdad on Wednesday.

"A premature withdrawal of American forces . . . would not only likely plunge this country into civil war, it would probably become the element that marks the beginning of regional war," said Lieberman, seeking to counter growing sentiment in Congress against the U.S. military presence in Iraq.

Lieberman said Iran would be tempted to support Iraqi Shiites in such a fight, Turkey might intervene in the Kurdish north, and Syria and Saudi Arabia could side with Sunni Arabs.

Correspondent Ellen Knickmeyer contributed to this report.