Iraqi Leaders Question U.S. Troops' Immunity

But allowing Iraqi authorities to try U.S. troops, who unlike contractors are subject to military courts-martial when accused of crimes, would be an unlikely, if not unprecedented, concession, legal experts said.

Immunity from prosecution is a common stipulation when U.S. forces are sent abroad. The Bush administration has declined to join the International Criminal Court at The Hague, in part out of concern that U.S. forces could be prosecuted for actions committed during foreign deployments. And a law passed by Congress in 2002 restricts U.S. involvement in U.N. peacekeeping missions unless American forces are deemed immune from prosecution.

Allison Danner, an international criminal law specialist at Vanderbilt University in Nashville, said that while the United States has occasionally allowed foreign governments to prosecute American troops, including in the Philippines and Japan, such decisions were made on a case-by-case basis, leaving the immunity intact.

"I can't see them allowing the Iraqi government to decide when that should happen," she said.

The case in Mahmudiyah, an insurgent stronghold south of Baghdad, has provoked a particularly strong reaction from Iraqi officials because of the attitude toward sex crimes in Islamic culture. U.S. soldiers are alleged to have raped a girl as young as 15 in her home, before fatally shooting her and three family members.

On Monday, former Army Pfc. Steven D. Green was arrested near Asheville, N.C., on federal charges of rape and murder. Army officials said Wednesday that Green, 21, was sent from his unit in Iraq back to the United States in April because of an unspecified "personality disorder" that was interfering with his performance as a soldier but that the Army was unaware at the time that Green was allegedly involved in the Mahmudiyah incident. Green officially left the Army on May 16, according to an Army spokesman.

At least four other U.S. soldiers still in Iraq are under investigation.

The U.S. Army unit responsible for Mahmudiyah, the 502nd Infantry Regiment, is the same unit whose soldiers were abducted by insurgents from a checkpoint at nearby Yusufiya in early June and later found dead, their bodies mutilated. Caldwell said Wednesday that there was not "any indication whatsoever" the incidents were linked.

Elsewhere in Iraq on Wednesday, U.S. and Iraqi forces continued a large-scale operation to free Tayseer al-Mashhadani, the Sunni lawmaker whose abduction led Sunni parties to boycott meetings of parliament.

Officials with the Iraqi Islamic Party, to which Mashhadani belongs, said Wednesday that the kidnappers had submitted demands, including the withdrawal of U.S. forces from Iraq on the party's timetable, the release of certain prisoners and a halt of attacks by Sunnis on Shiite mosques.

Mashhadani was abducted last weekend in a northern Baghdad neighborhood controlled largely by the Mahdi Army, a powerful Shiite militia believed by many politicians to have carried out the kidnapping. "Either they have done it or they didn't stop it," Othman, the Kurdish lawmaker, said Wednesday.

Staff writer Josh White in Washington and special correspondents Saad al-Izzi and Bassam Sebti in Baghdad contributed to this report.