BAGHDAD, Iraq — Insurgents fired a mortar at a ceremony today to hand over a presidential palace in Saddam Hussein's hometown, sending the American ambassador and the U.S. commander in Iraq scrambling for cover.

The mortar landed about 300 yards away from the palace in Tikrit, and no one was hurt. Ambassador Zalmay Khalilzad and Gen. George Casey sought safety within the palace, emerging a few minutes later to continue the ceremony.

Hamad Hamoud Shagtti, the Salahuddin provincial governor, received the keys to the palace from Casey, and a deputy governor raised the Iraqi flag over the building, part of a complex U.S. troops had occupied since 2003.

Afterward they took a tour of the building, which Saddam ordered built for his mother in 1991. It is considered the largest and most elaborate of the palaces built during his rule.

The mortar attack "was an ineffectual attempt to stop the progress that goes on everyday in Iraq," said Lt. Col. Barry Johnson, a spokesman for the U.S. command.

The palace is one of 18 in a complex of 136 buildings on more than 1,000 acres overlooking the Tigris River, the U.S. command said in a statement. With 1.5 million square feet of administrative and living space, the complex had served as a division headquarters for U.S. troops.

The command said the turnover highlights the "increased capability of the Iraqi government to administer and govern itself."

"Although 28 other coalition operating bases have already been turned over to Iraqi Security Forces control this year, the Tikrit Palace complex is the most significant transition of real estate thus far," the statement said.

Also today, the U.S. military said a U.S. soldier was killed by a roadside bomb during combat operations in western Iraq. The soldier assigned to the 2nd Marine Division died after the bomb detonated near his vehicle on Monday near Habaniyah, 50 miles west of Baghdad.

As of today, at least 2,098 members of the U.S. military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count. At least 1,638 died as a result of hostile action, according to the military's numbers. The figures include five military civilians.

Also, Iraq's anti-corruption commission today announced that members of the former government who are under investigation will not be allowed to run in next month's parliamentary elections.