U.S. soldiers fired a warning shot near a woman who "appeared to be signaling to someone" along a dangerous stretch of road north of Baghdad, but the bullet killed a young Iraqi girl, a military official said early Thursday.

The shooting took place Wednesday where several roadside bombs had recently been found in the volatile Diyala province. An exact location was not given in a military statement.

The girl appeared to be "around 10 years old," said Maj. Brad Leighton, a military spokesman.

There has been an increase in the use of women as suicide bombers in Iraq. But Leighton said preliminary reports indicated that soldiers didn't believe the woman posed a threat of being a bomber. Rather "they were afraid she was signaling to someone that the convoy was going by."

In its statement, the military said that "coalition forces fired a warning shot into a berm near a suspicious woman who appeared to be signaling to someone while the soldiers were in the area. A young girl was found behind the berm suffering from a gunshot wound."

Roadside bombs have been the biggest killer of American troops in Iraq.

Soldiers gave the girl medical attention and called for an evacuation. The girl died on the way to a medical facility, the statement said.

"Coalition forces take the loss of any innocent civilian life seriously and the incident will be thoroughly investigated," military spokesman Maj. Dan Meyers said in the statement.