FLAGSTAFF, Ariz. (AP) — An estimated 1,000 people who were forced to flee their homes because of a forest fire outside Flagstaff were allowed to return Wednesday.

Homeowners and their families began to trickle into the evacuated neighborhoods at 8 a.m. They had left their homes Sunday after the fire erupted just north of the northern Arizona city that is home to 60,000 people.

"We're very glad," said resident Lula Whitehair. "When we saw that fire coming, we thought the worst."

Jennifer Stanley and her husband returned home after spending the previous three nights in their camper.

After evacuating, they sat on the nearby U.S. Highway 89 to watch the fire, Stanley said, and she estimates flames came within a quarter-mile from her home in the Timberline neighborhood.

"You could see big like, 20-, 30-foot flames," she said. "We're like, 'OK, is that our house?'"

Crews had enough confidence in their fire lines to give the local sheriff the OK to lift the evacuation order, but he warned residents to be prepared to leave again if necessary.

The battle against the 22-square-mile Schultz fire was far from over. At least 10 miles of fire line still needed to be completed, and the blaze was just 20 percent contained. Crews Wednesday planned to improve the line on the southern flank of the fire to keep it from surging back toward the city, about five miles away.

To secure the line, crews were using several helicopters to drop material to ignite and burn out any forest fuels, said fire spokesman Eric Neitzel. Meanwhile, firefighters aided by air tankers and helicopters were trying to stop its growth to the north.

The east side of the San Francisco Peaks were covered in a light veil of smoke Wednesday morning, a relief compared to the heavy cloud that shrouded the mountains the day before.

Efforts to fight the blaze will likely continue for at least two weeks, incident commander Dugger Hughes said late Tuesday.

"It's going to be a long haul," he said. "But it's looking good."

Two heavy air tankers helped fight the blaze Tuesday, Neitzel said. The tankers, part of 19 under contract through the U.S. Forest Service to fight fires across the country, are capable of carrying more than 2,000 gallons of fire retardant used to slow the spread of fire. Nearly 1,000 firefighters were battling the blaze.

Authorities said the fire was started by an abandoned campfire, and strong winds quickly fanned the flames. No major injuries have been reported and no structures have burned.

The blaze tore though stands of ponderosa pine that ring the city and rise up the slopes of nearby mountains. Conditions are dry, despite record amounts of snowfall in the area last winter.

Authorities said a campfire also was to blame for a smaller fire in southeast Flagstaff that broke out Saturday. Campfires will be prohibited in three Arizona forests starting Wednesday.

The southeast Flagstaff fire was 80 percent contained Tuesday afternoon, and a third fire 11 miles northeast of Williams was expected to be fully contained Wednesday.

Arizona Gov. Jan Brewer toured the fire area Tuesday. Earlier in the day, she spoke with President Barack Obama, who assured her of the federal government's continued support in firefighting efforts. Two requests from the state for federal fire management assistance funds have been granted.