ROCKWELL CITY, Iowa (AP) — Eight people are facing trespassing charges after protesting in the path of the Dakota Access oil pipeline in northwest Iowa this weekend.

The Omaha World-Herald reports the Calhoun County Sheriff’s office says the arrests happened Saturday on a farm near Rockwell City, Iowa.

Ed Fallon, with the Bold Iowa group, says people who oppose the pipeline are frustrated it is moving forward.

The $3.8 billion pipeline is designed to carry oil 1,200 miles from western North Dakota through South Dakota and Iowa to a shipping point at Patoka, Illinois.

Hundreds of protesters have gathered in southern North Dakota near the Standing Rock Sioux tribe’s reservation to object to the project. That has led to clashes with law enforcement and more than 140 arrests in the past week.