Ventura County has joined a number of other California jurisdictions in equipping law enforcement vehicles with so-called hi-lo sirens intended to alert residents to evacuate neighborhoods in event of fires, floods and other disasters.

The European-style alternating two-tone sirens are much different than sirens normally heard in California.

“With wildfires increasing in frequency and severity, this distinct siren will serve as a powerful tool in efficiently notifying the public of an encroaching fire and the need to evacuate,” the Sheriff’s Office said in a statement Tuesday. “If residents hear the Hi-Lo siren in their community, it is a signal that they are in imminent danger and should evacuate immediately. “

A recently enacted state law authorizes use of such sirens to help in emergency evacuations.

A number of other sheriff’s agencies in counties including Lake and Napa as well as police departments in cities such as Santa Rosa have also added the sirens to their vehicles.