PASADENA – A brush fire burned about five acres in the Hastings Ranch area before it was fully contained Friday, authorities said.

The blaze was reported about 3:20 p.m. Friday and was 100 percent contained by 5 p.m., Fire Department spokeswoman Lisa Derderian said.

There are about 200 homes in the area, but none was threatened, Derderian said.

About 100 firefighters from Pasadena, the city and county of Los Angeles and the U.S. Forest Service battled the blaze from the air and from the ground.

Weather conditions were favorable with light winds and high humidity, Derderian said.

The cause of the fire was under investigation. Witnesses reported three juveniles running from the scene and they were detained for questioning, Derderian said.