MINNEAPOLIS (WCCO) — Several protesters were taken to the St. Louis County Jail Thursday after they locked themselves to machinery and an access gate at a Line 3 oil pipeline construction site.

The Northern Lights Task Force says 20 to 30 protesters gathered at and near the work site near Floodwood, with six of them locking themselves up. Deputies extricated and arrested them. A seventh person was also arrested for refusing to leave the site.

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All seven of the protesters are expected to be charged with gross misdemeanor trespass and obstructing the legal process. A 20-year-old Berkeley, California woman who was arrested Thursday was also arrested at the site last week.

The other protesters arrested:

* A 30-year-old woman from Fergus Falls
* A 19-year-old woman from Burlington, Vermont
* A 23-year-old man from Burlington, Vermont
* A 62-year-old man from Boise, Idaho
* A 22-year-old man from Pembroke, Massachusetts
* A 32-year-old woman from Orono, Maine

Dozens of people have been arrested at Minnesota Line 3 sites over the past several months. Protesters say the project is in violation of federal treaty rights, and it threatens bodies of water along its path.

Calgary, Alberta-based company Enbridge Energy started the $2.6 billion pipeline replacement project in Minnesota last December. The line begins in Alberta, Canada, before passing through a corner of North Dakota and into Minnesota. The line ends in Superior, Wisconsin. The Minnesota section of the project is the only part that still needs to be constructed.

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The Minnesota Court of Appeals heard arguments this week about the project, with opponents labeling the effort as unnecessary because of what they cite as a declining demand for oil. The court will likely make its ruling by early summer.