And now, KOMO 4 News has learned police have found gasoline and threatening notes at another construction site in nearby Clearview.

Someone left homemade burning devices and notes warning a housing developer near Clearview. Project manager Trevor Berring found several 2-liter pop-bottles filled with gasoline and some sort of igniting device left on the roadway in his development, along with a warning note.

At first, Berring said he thought the plastic bottles were from a meth lab. But investigators told him they were incendiary devices. He also said the note was from an eco-terrorist organization. He said he turned that note over to the FBI and indicated he did not know what it said.

The housing project, which is near Clearview's Highway 9 in south Snohomish County, had been the subject of earlier vandalism, but no threats.

Berring told KOMO 4 News he discovered the bottles at about 7:30 a.m. Tuesday when he came to work. He said they were obviously placed there between 6 o'clock Monday night and the time he found them.

FBI and ATF agents, who had been investigating the Clearview incident, showed up later near Snohomish, where two homes under construction were destroyed early Tuesday morning. A small fire was found in a third home, and an incendiary device was found in a fourth. Total damage to the homes was estimated at $800,000. Detectives are treating those fires as arson.

Local authorities are not saying that the two incidents are connected, but the FBI took over the investigation of the Snohomish fires Tuesday afternoon.

The FBI has not said yet if any notes were found in the Snohomish housing complex. All of the homes targeted were unoccupied.

The projects are being developed by different companies and spokesmen for both developers indicated they had received no warnings other than the ones found Tuesday near Clearview.

The FBI and ATF are continuing the investigation. In the meantime, workers at the Clearview site were installing additional lights and other security measures Tuesday afternoon.