Nearly 500 demonstrators who illegally entered the site of a nuclear power plant here were arrested during a two-day protest, according to the sheriff's office.

A handful of the protesters, who climbed mountains scaled fences to get in, remain at large in the heavily wooded area.

"There are quite a few of them still in the hills," said Sgt. Dan Okel of the San Luis Obispo County sheriff's office. "The terrain is very rugged and steep and we're sure not going to chase after them if they stay from the central plant site. If they're lucky, maybe a few of them will get snake bit.?

Nuclear power opponents were arranging to free the jailed demonstrators on bail.

The occupiers were part of a crowd of nearly 3,000 who gathered at a beach Sunday near this coastal town 200 miles north of Los Angeles to protest the continued construction of the $1.4 billion Diablo Canyon nuclear power plant. Located near several earthquake faults, the plant has been the subject of much local and statewide controversy.

The demonstrators tried yesterday morning to shut down the plant by stringing several sit-down blockades in front of the main gate. But deputies had little trouble breaking them up, and by afternoon a Pacific Gas and Electric Co. spokesman said that work at the plant, expected to go into operation early next year, was "continuing like any other day."