Police swiftly seized the shovels Monday of animal-rights protesters who had just begun to plunge the blades into a grassy courtyard above underground animal-research labs at UC Berkeley.

The activists from In Defense of Animals did not resist, and their effort appeared to have been symbolic. Organizers said the lunch-hour protest was one of several demonstrations internationally for World Week for Animals in Laboratories.

"It's pretty disgusting to think about what's happening beneath our feet -- monkeys having electrodes implanted in their brains, kittens having their eyes sewed shut," said activist Jennifer Blum.

Before the attempted dig with four shovels at the Northwest Animal Facility, 19 protesters held banners and anti-vivisection posters along nearby Oxford Street.

Organizer Nora Kramer said experimenting on animals doesn't produce useful results for humans and such research diverts funds from other needs, such as feeding starving children.

Officials at UC Berkeley, long a target of animal-rights activists, say animal research has a long history of producing life-saving treatments for humans. They say new lab facilities and reforms in animal care have produced a high standard of humane treatment, winning the campus approval from the American Association for Accreditation of Laboratory Animal Care.

"The truth is that most researchers would love it if they didn't have to use animals," said Helen Diggs, head of the campus' Office of Laboratory Animal Care.

She said the campus does no research on kittens but acknowledged that monkeys are used in "neurologic studies related to vision." She declined to describe the research, saying, "Some of it isn't very pretty. Is it necessary to get the cure that may save someone's life? Yes, it might be."

She said that open-heart surgery on humans isn't "pretty" either but can be necessary and that it was developed through research on dogs and pigs. Many drugs, ranging from insulin to Tylenol, were developed through animal research, she said.

In Defense of Animals argues that alternative drug-testing methods could prove equally effective, but researchers disagree.