(CNN)A fast-moving fire erupted in Southern California on Wednesday, exploding from 25 acres to nearly 1,000 acres within five hours.
Mandatory evacuations have been issued for parts of Murrieta as the raging blaze creeps closer to residential areas, shooting plumes of smoke and orange flames into the sky. Residents in those areas have been asked to take their pets to a local animal shelter.
At least 400 homes, or about 1,200 residents, are under mandatory or voluntary evacuation orders, the incident information spokesman told CNN. The Murrieta Valley Unified School District is closed Thursday.
More than 500 firefighters are fighting the blaze dubbed the Tenaja fire, after the street on which it started.
Tenaja was first reported minutes before 4 p.m. local time Wednesday, when it was 25 acres. By about 9 p.m., it had scorched 994 acres and was 5% contained, the Riverside County Fire Department said. One football field is roughly 1.32 acres.
Murrieta is about 80 miles from Los Angeles and has a population of 104,000. The cause of the fire is under investigation.