Why are American troops killing Iraqi soldiers?

U.S. troops opened fire at civilian cars Saturday night in Baiji town, some 200 km north of Baghdad, killing three people, who turned out to be U.S.-trained Iraqi army soldiers, a source from the Iraqi-US liaison office in Tikrit told Xinhua on Sunday.

"The Multi National force opened fire last night at four civilian cars travelling on the main road between Tikrit and Baiji, setting fire to all the cars," the source from the Joint Coordination Center in Tikrit said.

The U. S. shoot-out killed three people and wounded four others and the U.S. soldiers detained six other people, who turned out to be Iraqi soldiers travelling to their base in Samarra in the south of the country, the source said.

He said the Iraqi soldiers' cars were surprised by a U.S. military convoy travelling wrongly on their side of the two-side road and opened fire. Enditem

This seems somewhat counter intuitive. How are we ever going to be able to bring our troops home if we kill our replacements?

I just noticed that this article came from a Chinese newspaper. They seem to be paying very close attention to our Iraq situation. I am sure they are learning a lot about our capabilities and our weaknesses.