An animal-rights activist was arrested Friday on charges she planted a radiocontrolled pipe bomb in an apparent attempt to kill the head of a company that experiments on dogs, police said.

Fran Stephanie Trutt, 33, of New York, was captured shortly after midnight as she left the grounds of U.S. Surgical Corp., police said.New York City police later removed two 3-by-6 inch pipe bombs from Trutt's home in Queens, "one with a fuse, one with a radio," Detective Joseph McConville said. She had initially given her parents' address in suburban New Hyde Park, N.Y., police said.

The New York-based Fund for Animals, which had filed a complaint over the dog experiments, said it had no connection with Trutt.

"We were horrified to learn of this," said Julie Lewin, the organization's Connecticut coordinator. "We in no way condone any terrorism. Violence toward people does not help animals."

"Ms. Trutt is a self-styled member of several animal rights groups and considers the policies of U.S. Surgical to be an affront to animal rights," said police Lt. Jeff Finch.

She was charged with attempted murder, possession of explosives and manufacturing a bomb, and was being held under $500,000 bond pending an appearance Monday in Norwalk Superior Court, police said.

Police had staked out the company, which produces surgical stapling devices, after receiving information that it might be the target of violence, Finch said.

Officers saw Trutt enter the grounds with a package and leave it in some bushes about 10 feet from Chairman Leon Hirsch's vacant parking space, Finch said.

Trutt was carrying a radio-controlled detonator for the bomb when she was arrested, he said. Finch initially said Trutt planned to explode the bomb as Hirsch walked into building, but he said later he didn't know when she planned to explode the bomb or whether Hirsch was definitely the target.

He described the device as a "sophisticated bomb capable of killing anyone near it." A Stamford police bomb squad removed it.

About 200 people were working in the plant overnight, Hirsch said.

The potential loss of life made the incident the most serious of more than 100 animal rights actions, including break-ins, vandalism and demonstrations, over the past decade, said Frankie Trull, president of the Washington, D.C.-based Foundation for Biomedical Research. The most serious previous incident was a $3.5 million arson at the University of California at Davis in 1987, Trull said.

The FBI is investigating for possible federal charges, including terrorism, police said.

U.S. Surgical, which employs 2,600 people nationwide, conducts experiments on about 1,000 animals, mostly dogs, a year, Hirsch said. The animals, which are obtained from U.S. Department of Agriculture farms, are destroyed after experiments, he said.

State health officials last month upheld the company's use of anesthetized live dogs to demonstrate its equipment for surgical stapling, a process that replaces stitches to close wounds and incisions.

Hirsch said he had never spoken to or received letters from Trutt.

"I think what we and other companies should be doing is telling the world what these animal activists are really like," Hirsch said.

"The public thinks they're a wonderful group of little old ladies, protecting puppies and pound dogs," he said. "But nothing could be further from the truth. These are hard-core animal extremists who believe the rights of animals supersede the rights of humans."