Protesters again have locked themselves to steel towers used to construct the Highway 101 Willits bypass, halting work in wetland areas.

Work on other areas of the project were unaffected by the actions that began Tuesday morning, Caltrans officials said.

It was the fourth time people have used locking steel tubes to tie themselves to the 100-foot towers used to drive wick drains into the ground, said one of the protest organizers, Naomi Wagner.

The last time, Will Parrish spent 10 days high up in a crane before he was removed July 1.

This time the cranes were resting on the ground when two protesters skirted security officers and entered the construction area at about 5:30 a.m. Tuesday. They crept in as other protesters distracted officers, according to Caltrans officials and protesters.

It's unknown when officers with specialized equipment will arrive to remove them, said Caltrans spokesman Phil Frisbie. Three other protesters, including a Willits news photographer, were arrested Tuesday morning, Wagner said.

The 5.9 mile, $210 million bypass is being built to skirt the city of Willits, where traffic regularly slows to a crawl as Highway 101 narrows to two lanes through downtown. Proponents say it's necessary to reduce traffic congestion and restore the city's small-town feel. Opponents say it is an unnecessary, costly and ugly mistake that will irrevocably damage wetlands and streams.

More than 30 arrests have been made since April.

Caltrans officials say the protests so far have cost taxpayers more than $1.2 million.