WEST COVINA, Calif.  —  Fires destroyed dozens of SUVs (search) and a warehouse at an auto dealership Friday, and vehicles there and at three other dealerships were spray-painted with slogans such as "Fat, Lazy Americans."

"With all the evidence ... it's highly likely it's an arson fire," said Rick Genovese, fire marshal for West Covina, a Los Angeles suburb.

The radical group Earth Liberation Front (search) issued an unsigned e-mail Friday calling the incidents "ELF actions," and the FBI was investigating the dealership fire as domestic terrorism, Police Chief Frank Wills said.

The underground group has claimed responsibility for a slew of arson attacks (search) against commercial entities that members say damage the environment. It is suspected in a multimillion-dollar arson fire Aug. 1 that destroyed a five-story apartment complex under construction in San Diego, though an ELF e-mail claimed the group had not been in contact with those responsible in that case.

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The blazes at the Clippinger Chevrolet dealership broke out about 5 a.m. Friday. Flames destroyed about 20 vehicles, mostly Hummer H2s, which are luxury SUVs patterned after the military's workhorse Humvee. Another 20 vehicles were badly damaged. A separate blaze caved in a warehouse roof.

There were no reports of injuries, but damage was estimated at $1 million.

SUVs at dealerships in nearby cities of Arcadia, Duarte and Monrovia were also vandalized, though there were no other fires.

Among the slogans written on the sides and hoods of vehicles were "I (heart) Pollution" and "American Wastefullness." "ELF" was written on at least one vehicle.

General Motors Corp. (search) spokesman Brian Akre called the blaze a "reprehensible criminal act" and said the Detroit-based company, whose brands include Hummer (search) and Chevrolet, was thankful that the fire didn't result in injuries.

"If this was some kind of misguided attempt to make a political statement, those responsible should know that committing arson and putting property and people in danger is not the way to gain public support for their position," Akre said.