FORT CARSON, Colo. (AP) — A wildfire that destroyed at least two homes in southern Colorado was sparked by an Army aviation training exercise that used live ammunition, the military said Monday.

The fire started on Fort Carson amid dry, windy weather on March 16 and spread to private land, charring 5 square miles (13 square kilometers) before it was contained. It prompted evacuations of residents and livestock, but no injuries were reported.

The National Weather Service had issued a fire warning that day because of the conditions.

The Army was "mitigating risk and altering training" before the blaze and would continue to do so when fire danger is high, the post's commander, Maj. Gen. Randy A. George, said in a written statement. He said Fort Carson's regulations, as well as orders for training missions, outline steps to reduce the chances of flames.

The statement did not give details or explain why Fort Carson waited 10 days to acknowledge that the exercise used live ammunition. A post spokeswoman didn't immediately respond to an email seeking clarification.

Some residents who live near Fort Carson criticized commanders for conducting the exercise despite the fire danger.

"The Army is supposed to protect the American public, but it for sure doesn't feel like we're being protected," said Samuel Saling, whose home was one of about 250 evacuated during the blaze.

"They should have all hands on deck, considering how many troops are stationed there that are trained to deal with this type of situation," he told the Colorado Springs Gazette.

The post commander said the Army needs to balance its training needs with the safety of its neighbors. Fort Carson previously said the March 16 training exercise was preparing soldiers for deployment.

The Army said residents could submit claims for reimbursement for property damage to Fort Carson.

The fire also ignited old tires that were fashioned into a fence on private land. Burning tires can release hazardous smoke, and the U.S. Environmental Protection Agency was awaiting the results of tests on the tire debris to see if it needed to be taken to a hazardous waste dump.