Conflicting reports surround the killing of 15 Afghan civilians in Kandahar province this weekend.

On the one hand, witnesses told Reuters they saw a group of U.S. soldiers arrive at their village in Kandahar's Panjwayi district on Sunday around 2 a.m. local time, enter homes, and open fire.

On the other hand, an Afghan minister earlier told Reuters that a lone U.S. soldier had killed as many as 16 people when he burst into homes in villages near his base in the middle of the night.

Panjwayi district is about 22 miles west of Kandahar city. The district is considered the spiritual home of the Taliban, according to Reuters.

About the only thing clearly visible through this particular fog of this particular war is that 15 Afghan civilians are dead, as The Associated Press reported one of its photographers was shown their bodies -- men, women, and children -- by local villagers.

Also clear is that this incident is likely to add to the already-significant tensions between Kabul and Washington.

In any case, NATO's International Security Assistance Force apologized for Sunday's shootings.

I wish to convey my profound regrets and dismay at the actions apparently taken by one coalition member in Kandahar province. One of our soldiers is reported to have killed and injured a number of civilians in villages adjacent to his base. I cannot explain the motivation behind such callous acts, but they were in no way part of authorized ISAF military activity, Lt. Gen. Adrian Bradshaw, the deputy commander of the ISAF in Afghanistan, said in an online statement.

Bradshaw added: An investigation is already under way, and every effort will be made to establish the facts and punish anyone responsible as appropriate. In the meantime, our thoughts and prayers are with those caught in this tragedy.