MALTBY, Wash. -- Inflammatory graffiti found in Snohomish County this week garnered the attention of the FBI, reported KIRO 7 Eyewitness News.

Authorities said graffiti found in an industrial park in Maltby could be the work of the eco-terrorist group ELF, or the Earth Liberation Front.

KIRO's partner, the Daily Herald, said the message seemed to reference the radio station KRKO and its owners, the Skotdal family.

"If you continue to risk killing children, mother earth and her creations, all your holdings are targets. Rise up earth children, ever, ever, ever, ever so carefully. They watch everything. The time is now. Authentic ELF? Ask ATF/FBI about restricted water mains. Little water, better burn. ELF," the graffiti read.

The graffiti is the third act of vandalism in Snohomish County in the last year and a half.

Last month, two towers of the radio station KRKO was knocked over. ELF, which claimed responsibility for the sabotage, left a sign at the scene.

In March 2008, a massive arson fire burned houses on the Street of Dreams in the Maltby area, causing millions in damage.

ELF claimed responsibility, leaving a sign blasting the builders for not using green practices to build the homes.

The graffiti left this week appears to make reference to more possible fires.

A spokesman for the Master Builders Association, Mike Pattison, says it takes the message as a serious threat. KRKO owner Andy Skotdal declined to comment. He is replacing the toppled towers.