BILLINGS, Mont. (AP) — Crow Agency firefighting officials on Friday banned open burning on the southeastern Montana reservation following a string of small, early-season wildfires.

Fire crews responded to 13 small fires in the last week, including at least three started by children and four sparked by a truck pulling another vehicle on a frontage road along Interstate 90, according to fire officials with the Bureau of Indian Affairs in Crow Agency.

Small fires flared up near Lodge Grass, Wyola, Pryor and Crow Agency, Yellowstone Public Radio reports. A burn just north of the Wyoming border on on Sunday spread to 16 acres near Wyola.

Late March brings its own fire season, with warm temperatures and cured grasses creating wildfire conditions before the landscape starts to green up, officials say.

Warm, dry conditions are forecast through the weekend in much of eastern Montana, with colder temperatures and snow in western areas of the state.

Officials say response times on fires may be slower as they prioritize keeping firefighters healthy.