A wildfire burning in southern Arizona has spread to 5,500 acres Sunday and is now 90 percent contained.
The fire was 4,200 acres Saturday and only 10 percent contained.
The National Weather Service in Tucson said smoke from the fire was visible on radar.
— NWS Tucson (@NWSTucson) May 7, 2016
A release from the U.S. Forest Service says the Cumero Fire ignited around 9:30 a.m. Friday next to Cumero Mountain, about 10 miles northeast of the Arizona border town of Sasabe.
The fire is mostly in the Coronado Forest, but has also burned several hundred acres of the Buenos Aires National Wildlife Refuge. So far no structures have been damaged.
Approximately 160 personnel, including five wildland fire crews and five engines, had been assigned to the scene Sunday.
Early Sunday, two helicopters assisted in dropping water to slow the fire's progress, but since full containment is nearing the helicopters are no longer being used Sunday night.
Winds throughout the weekend helped the fire spread among grass and brush, and authorities said the fire's future growth potential remained high as of Sunday morning.
Officials from state, federal and local agencies responded to the scene.
Authorities said the fire was caused by human activity, and was under further investigation.