MINNEAPOLIS (WCCO) — Thirty-one Line 3 oil pipeline protesters were arrested Tuesday in Hubbard County.

The sheriff’s office says protesters began arriving at the Enbridge Energy equipment site in Henrietta Township just before 7:30 a.m., with the first carload of protesters allegedly forcing a semi-truck to stop on County Road 11. Protesters then attached themselves to the truck’s rear axle and to the top of its trailer.

READ MORE: ‘Water Is Life, Protect The Wildlife’: Hundreds Protest Enbridge’s Line 3 Replacement Pipeline In Northern Minnesota

Arrests began after deputies say they witnessed protesters “yelling vulgarities, being a traffic hazard, and refusing to leave,” which the sheriff’s office says were all offenses that were in violation of the state’s Public Nuisance and Unlawful Assembly laws.

Hundreds of protesters have been arrested since pipeline construction resumed in Minnesota in early June.

Enbridge’s 1,100-mile-long Line 3 replacement pipeline would transport tar sands oil from Alberta, Canada through northern Minnesota, with its final destination in Superior, Wisconsin. The original Line 3 was constructed in the 1960s, with part of the new line running alongside the existing route. The pipeline’s Canadian and Wisconsin sections are already finished. Just half of Minnesota’s section remains incomplete.

Sections of the Enbridge Line 3 pipeline on the construction site on the White Earth Nation Reservation (credit: Kerem Yucel/AFP via Getty Images)

READ MORE: ‘They’re Shoving A Pipe Down Our Throat’: Inside Winona LaDuke’s Fight Against Line 3

Legal challenges and organized opposition to Line 3 have been ongoing for years. Opponents say the pipeline will endanger more than 200 bodies of water in Minnesota, including the Minnesota and Shell rivers. And new paths would be carved through several Native American communities in Minnesota, including three reservations near Bemidji.

The Minnesota Department of Commerce’s lawsuit to stop the line was shot down Monday by the Minnesota Court of Appeals. The Minnesota Pollution Control Agency has also been sued for giving Enbridge water quality certification for the project.

Enbridge Energy officials say the project creates a more efficient way to transport oil, as well as boosting state tax revenues and creating thousands of job. Enbridge says it’s also in negotiations with the Leech Lake Band of Ojibwe to move the line off its reservation.

READ MORE: Jane Fonda Visits Minnesota To Protest Line 3 Pipeline