FLAGSTAFF, Ariz. – The second wildfire to hit this forested city in two days drove residents from more than 1,000 homes Sunday, and authorities arrested a man they say caused the first blaze by dumping coals from a campfire on the ground.

Coconino County authorities asked residents of 1,044 homes in three neighborhoods north of the city to leave because of the latest fire. The first wildfire, burning 350 acres in southeastern Flagstaff, forced the evacuation of about 170 homes, briefly shut down a hotel and remained uncontained Sunday.

Authorities knew of no buildings that had been burned. U.S. Route 89 northeast of the city was closed because of smoke from the second fire, and each blaze forced an animal shelter to evacuate.

Crews on the ground, in air tankers and in helicopters were trying to protect homes as flames could be seen scorching treetops on nearby ridges.

“There’s a pretty impressive towering column of smoke,” said Coconino National Forest spokeswoman Karen Malis-Clark.

The American Red Cross set up a shelter at a Flagstaff middle school for residents displaced by both fires.

Fire officials did not know what sparked the second blaze. A California man was arrested Sunday on suspicion of starting the fire that erupted Saturday by leaving behind hot coals at a campsite in a wooded area about two miles from downtown Flagstaff.

“As far as we understand, this was not a deliberate act. It was a careless act,” said Kimberly Ott, spokeswoman for the northern Arizona city of about 60,000.

Randall Wayne Nicholson, 54, was arrested on a misdemeanor charge of burning of a wildland, Ott said. Nicholson, whose hometown was not immediately available, was being held on $2,500 bond at the Coconino County jail.

The fire Nicholson is accused of starting quickly spread up a hill and threatened homes in two neighborhoods. Crews worked overnight and Sunday to protect structures and establish a perimeter around the blaze, but Coconino County spokeswoman Joanne Keene said fire officials have not declared any part of the fire contained.

Fires also had crews busy Sunday near Williams, Ariz., and in Colorado and New Mexico.

High winds and rugged terrain kept ground crews and aircraft from getting close to a wildfire in southern Colorado’s Great Sand Dunes National Park.