FOUNTAIN, Colo. — Authorities say burning tires that ignited when a wildfire spread from Fort Carson are producing toxic smoke that could force evacuations.

The Colorado Springs Gazette reported Tuesday the Environmental Protection Agency has taken charge of managing the tire fire.

The smoke prompted an elementary school about a mile from the fire to cancel classes.

The wildfire broke out on Fort Carson Friday in dry, windy weather. It spread to private land, destroyed three homes and scorched 5 square miles (13 square kilometers).

At least 250 homes were evacuated.

The wildfire is contained and most residents have been allowed to return, but the tires are still burning.

An Army training exercise was underway when the fire broke out. Fort Carson hasn’t said whether it involved live ammunition or whether it caused the fire.

Information from: The Gazette,