Authorities say a wildfire sending massive plumes of smoke into the sky north of Los Angeles has knocked out power to more than 160 homes and prompted evacuations in a number of mountain communities.

Forest Service spokeswoman Rachel Mailo says mandatory evacuations have been extended Saturday into neighborhoods in the canyons on the northwestern edge of Altadena. In La Canada Flintridge, more than 150 homes on the slopes of the San Gabriel Mountains are under mandatory evacuation orders.

The blaze has scorched nearly 12 square miles of dry forest and is only 5 percent contained.