BISBEE, Ariz. (AP) — A wildfire burning in southeastern Arizona had grown to about 12.5 square miles (32 sq. kilometers) by Friday night.

The fire about 2.5 miles (4 kilometers) north of Bisbee was sparked during a dry-lightning storm on Thursday night.

The Arizona State Forestry Division said Friday the fire had spread from about 600 acres (243 hectares) on Friday morning to 8,000 acres by 8 p.m., the agency said.

The fire on Mule Mountain in Cochise County consumed scrub oak and tall grasses.

More than 130 fire personnel were working on the fire. Crews were expected to continue building fire lines and using air suppression. Additional resources were expected to arrive Saturday.

The division said no structures were threatened.