U.S. jets shot down an Iranian unmanned surveillance aircraft last month over Iraqi territory about 60 miles northeast of Baghdad, the U.S. military said.
A U.S. statement said the Ababil 3 was tracked for more than an hour before U.S. jets shot it down "well-inside Iraqi airspace." The statement said the aircraft's presence over Iraqi airspace "was not an accident."
An Iraqi official said the Iranian aircraft went down near the Iraqi border town of Mandali. He spoke on condition of anonymity because he was not authorized to talk to the media.
The U.S. has frequently accused the Iranians of supplying weapons, training and money to Shiite extremist groups opposed to the U.S. military presence and to the U.S.-backed Iraqi government.
Iran has denied links to militant groups inside Iraq and says the instability in this country is due to the U.S. "occupation."
Also Monday, a U.S. soldier was fatally injured during combat operations in the capital, the U.S. said in a statement. No further details were released.
It was the first combat death reported by the U.S. military in Baghdad this month and the first among U.S. forces nationwide since March 7 when a soldier was killed in the Tikrit area.
U.S. casualties have dropped sharply since Iraqi soldiers and police have taken a greater role in security. President Barack Obama has pledged to withdraw all U.S. combat troops from Iraq by September 2010.
American combat troops are due to leave bases in Baghdad and other cities by June 30 under an agreement that provides for all U.S. forces to leave the country by the end of 2011.
Prime Minister Nouri al-Maliki told The Associated Press on Sunday that U.S. troops may stay in some areas that are not completely secure even after the June 30 date.
He did not identify those areas, but U.S. and Iraqi troops are still trying to secure Mosul, the country's third-largest city where al Qaeda and other Sunni militant groups remain active.
Meanwhile, residents of the Kurdish town of Halabja marked the 21st anniversary of the March 16-17 poison gas attack by Saddam Hussein's forces against Kurdish separatists.
The 1988 attack killed thousands of people and was the biggest use of chemical weapons against a civilian populated area in history.
Local officials and victims' relatives placed wreaths on a monument to the dead.
"The anniversary has become etched in the memory of many people," said Aras Abbadi, who lost 21 relatives in the attack. "Every year, we wait for the anniversary and condemn that deplorable attack committed by a dictatorial regime against its own people."
Another participant, Mariam Saleh, 59, pointed to a photograph on display that shows a truck full of victims.
"My family was in that truck," she wept.
By Associated Press Writer Robert H. Reid; AP Writer Yahya Barzanji contributed to this report from Halabja