SANTA BARBARA - HELPED by cooler, moist weather, firefighters gained the upper hand on a wildfire that has burned dozens of homes and forced thousands of Santa Barbara residents to flee since it was ignited, apparently by power tools, nearly a week ago.

As of Sunday, fire crews had established containment lines around more than half the blaze, which has charred over 8,700 acres (3,520 hectares) in the foothills above the scenic and largely affluent coastal town 90 miles (145 km) northwest of Los Angeles, authorities told reporters.

Less than a third of the fire had been corralled by late Saturday, after hot, dry, erratic winds abated, giving way to lower temperatures, fog and mist blowing in from the ocean. Firefighters also made headway overnight. With the immediate threat to the city proper averted for the time being, most of the remaining 15,000 evacuees were permitted to return to their homes but were advised to remain ready to flee again at a moment's notice.

'We are not out of the woods yet,' said Kelly Goethe of the California Department of Forestry and Fire Protection. 'One little spark in 50-mph (80-kph) winds and we're right back to where we were a couple of days ago.' He said dangerous 'sundowner' winds, which typically gust through mountain passes from the desert after nightfall, could reappear in the next couple of days. For that reason, most of the 4,200 personnel on the fire line would remain in place for the time being.

Later in the day, state fire officials issued a statement saying the cause of the fire 'appears related to the use of power tool equipment involved in vegetation clearance,' and asking the public for information about anyone who may have engaged in such activity near a trail where the fire began.

Some 30,500 people, about a third of Santa Barbara's population, had been under mandatory evacuation orders at the height of the fire threat on Friday.

According to latest estimates, the so-called Jesusita blaze, the fourth major wildfire to strike Santa Barbara in two years, has destroyed 31 homes and damaged nearly 50 others.

No civilian casualties have been reported since the blaze began Tuesday but 18 firefighters were hurt, including three who suffered severe burns and smoke inhalation when they were overrun by flames on Wednesday, fire officials said. -- REUTERS