BENSON, Ariz. — The Latest on a series of wildfires burning across the state of Arizona (all times local):

4:50 p.m.

Officials say wildfires that caused evacuations in two southern Arizona neighborhoods have merged.

Gerry Perry, a spokesman for the Coronado National Forest, says two fires caused by lightning in the mountains east of Benson are being managed as one as of Friday.

The blaze has destroyed an empty home in Cochise County and charred about 12 square miles (31.08 sq. kilometers) since it started Tuesday afternoon.

Perry says 220 firefighters and 25 engines are managing the wildfire.

He says there’s no estimate for when the blaze will be contained and he expects it will be a long fight.

County Sheriff’s spokeswoman Carol Capas said Friday morning about 30 families in Cochise Stronghold and about half of Dragoon’s residents have evacuated their homes and more are prepared to leave.

10 a.m.

The National Weather Service says high winds and low humidity could cause fires to spread more easily in northwest Arizona Friday afternoon and evening.

The heightened fire danger means campfires and other activities that could start fires should be avoided. The area under a so-called “red flag warning” includes the entire Kaibab National Forest and a fire burning north of Flagstaff that closed a highway.

A section of State Route 180 is closed about 10 miles north of Flagstaff because smoke from the fire burning on the slopes of Kendrick Mountain restricts visibility.

The fire started last week following a lightning strike in a wilderness area just west of the state highway. The fire grew significantly Thursday because of high winds and has consumed nearly three square miles.

8:10 a.m.

Several hundred residents of Cochise County are still out of their homes or prepared to leave at a moment’s notice because of wildfires that already destroyed one home.

Cochise County Sheriff’s spokeswoman Carol Capas said Friday about 30 homes in Cochise Stronghold remain evacuated. An area of Dragoon has also been evacuated and the rest of the community of more than 200 residents is ready to flee.

The Cochise Stronghold evacuation was due to a wildfire that has burned about a third of a square mile. The blaze near Dragoon has charred about 5.4 square miles (14 sq. kilometers).

Authorities say the fires in the mountains east of Benson could merge.

Another fire has forced the closure of the highway between Flagstaff and the Grand Canyon in northern Arizona.