WOODINVILLE, Wash. -- Four large homes burned at a "Street of Dreams" model home development north of Woodinville, Wash. early Monday morning, investigators said.

Signs indicate it was the work of eco-terrorists.

Snohomish County District Seven Chief Rick Eastman said that a sign with "ELF" spray-painted on it was left at the scene.

A banner claiming responsibility by the radical environmental group Earth Liberation Front states: "Built green. Nope Black! Mcmansions and CDs are not Green."

Builder Grey Lundberg said he cannot understand why an envionmental group would strike the home he built; it incorporated the lastest in eco-friendly standards and even won environmental awards.

No firefighters were injured.

ELF, or Earth Liberation Front, has claimed responsibility for other arsons, including one at the University of Washington in 2001 for which a woman is now on trial in Tacoma.

Eastman also said that the fires are suspicious because they were set in multiple places in separate homes.

 Also: Tre Arrow extradited to Portland

 Video: Tre Arrow's sister talks to KGW

There were no reports of injuries in the three-alarm Monday morning fire. Eastman said some of the homes were still under construction.

Eastman said one is a total loss and two homes were substantially damaged. He said fires also were set at a total of six homes.

An award was offered for information leading to an arrest in the case. The tip hotline is 800-55-ARSON.

The Street of Dreams is an annual showcase of luxury homes in the Seattle area. The latest development is off Highway 522 at Echo Lake Drive.