The Earth Liberation Front (ELF), one of the most active ecoterrorist groups in the United States, has claimed responsibility for planting incendiary devices at two construction sites in Northern California.

Five of the devices, which failed to ignite, were found in a building under construction in Auburn on January 12, 2005.  Investigators indicated that they were capable of causing extensive fire damage and possible injury to construction workers.

Similar devices were found in late December at a housing development in Lincoln, California, according to the FBI. 

In a letter sent to several area newspapers, ELF says that it acted "in honor of everyone who has felt helpless to sprawl and development, everyone who feels their rural lifestyles are being threatened by these mass-produced designer communities…"

The Auburn office building was targeted as "a statement against work and the horror of the (cubicle)," according to the letter.

ELF threatened additional actions and also claimed solidarity "with all those engaged in sabotage and resistance around the world; Iraq, Afghanistan, Palestine, Mexico, Brazil among others especially the indigenous struggle against the onslaught of modernization."

ELF has claimed responsibility for hundreds of acts of property damage.  The most damaging occurred on August 1, 2003, when arsonists burned down a housing complex under construction in San Diego, destroying a five-story building and 100-foot-high crane; losses were estimated at $50 million.