Five more protesters were arrested Wednesday after halting work on Caltrans' Willits bypass project, activists said.

The protesters blocked crews installing vertical "wick" drains on the site, said Jamie Chevalier, spokeswoman for Redwood Nation Earth First.

A large group sat down in front of construction equipment at about 10 a.m. and refused to move, preventing workers from going forward, Chevalier said. They remained until 2 p.m., when they were arrested by CHP officers on trespassing charges, she said.

"They shut down the entire job for the day and all the workers went home," Chevalier said.

The CHP did not respond to a request for comment about the arrests.

They were the first protesters arrested at the controversial project since Memorial Day weekend. Authorities have now made 30 arrests since work began in January, Chevalier said.

Up to eight tree sitters have occupied surrounding trees at various times but only one remains, she said.

Protesters believe the $221 million project will hurt the environment and result in the closure of two dozen Willits businesses.

On Wednesday, 50 protesters walked onto the site and sat down in front of an 80-foot-tall tower driving the wick drains into the ground, Chevalier said.

CHP officers responded and then left for two hours, she said.

They returned and arrested five people, including a local business owner and three Willits residents. The fifth person was from Humboldt County, she said.

"This is an assault on both the economy and ecology of our valley," said Dannielle Fristoe, owner of Roadhouse Music in Willits, who was arrested. "Main Street jobs are permanent jobs. The temporary boost from construction isn't worth it."

Chevalier said the CHP responded to Wednesday's protest with 10 patrol cars.