The professor's car was the target of a suspicious arson as it was parked outside his home on Saturday, FBI spokeswoman Laura Eimiller said. No one was hurt.
The Animal Liberation Front posted a message in which the Animal Liberation Brigade claimed responsibility for the bombing on its Web site Monday. The bombing is the latest in a series of violent acts against UCLA researchers, university spokesman Phil Hampton said.
UCLA and several local and federal agencies have offered a combined $445,000 in rewards for information on five separate incidents aimed at UCLA faculty who use animals in medical research.
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"The actions of extremists who use violent and illegal tactics are utterly reprehensible and beyond contempt," UCLA Chancellor Gene Block said.
In April, the university obtained a preliminary injunction that prohibits the harassment of staff involved in animal research and bans posting researchers' personal information online and in fliers.