Some residents in Piru in Ventura County were under evacuation orders Saturday as firefighters battled a brush fire.

The Holser Fire — now 167 acres with 0% containment — was reported just after 1 p.m. in a remote area near Lake Piru, Cal Fire said. Crews stopped the forward progress of the fire around four hours later but were expected to continue working throughout the night, focusing on building containment lines and extinguishing hotspots.

Evacuation orders were downgraded to warnings in the following zones:

Los Angeles County

CAS-GOLDENSTATE-B

CAS-GOLDENSTATE-D

CAS-OAKCANYON

CAS-VALVERDE-B

Ventura County

PIRU-01

PIRU 10

PIRU-14

CDER-01

LAKP-02

LAKP-04

LAKP-05

LAKP-06

Crews on the ground and on helicopters were working to extinguish the blaze. Officials say there was a possible threat to powerlines and infrastructure, including the Piru Dam.

It’s unclear what started the fire.