CAMARILLO, Calif.—A Southern California wildfire has destroyed 132 structures, mostly homes, in less than two days, fire officials said Thursday as raging winds were forecast to ease.

The fire started Wednesday morning in Ventura County and has grown to about 32 square miles at 5 percent containment. Its cause has not been determined.

Ten people have been injured in the course of the fire, Ventura County Sheriff James Fryhoff said. Most of them suffered from smoke inhalation or other non-life-threatening injuries.

Fire officials said 88 other structures were damaged but did not specify whether they had been burned or affected by water or smoke damage.

Some 10,000 people remained under evacuation orders Thursday as the Mountain Fire continued to threaten some 3,500 structures in suburban neighborhoods, ranches and agricultural areas around Camarillo in Ventura County.

County fire officials said crews working in steep terrain with support from water-dropping helicopters were focusing on protecting homes on hillsides along the fire’s northeast edge near the city of Santa Paula, home to more than 30,000 people.