A Minnesota Sheriff’s Office says that dozens of pipeline protesters were placed under arrest earlier this week after blocking a semi truck and “disabling” the vehicle by attaching themselves to equipment.

So far this month, hundreds of protesters have been arrested for trying to block construction on the Enbridge 1,100-mile-long Line 3 replacement pipeline in Minnesota since work resumed on the project in early June. Protesters believe that the pipeline will threaten to contaminate more than 200 bodies of water in Minnesota and argue that the pipeline would run through Native American protected land.

A recent clash between protesters and a truck driver hauling heavy drilling equipment occurred on the morning of June 15 in Henrietta Township, Minnesota.

According to the Hubbard County Sheriff’s Office, around 7:30 a.m., officers received a call about pipeline protesters gathering at an Enbridge equipment site located on Hubbard County Road 11.

The caller told police that “a van had pulled in front of a semi tractor-trailer causing it to abruptly stop on the highway. The occupants of the van quickly got out with one individual crawling underneath the semi trailer and attaching herself to the rear axle with an apparatus called a “Sleeping Dragon”, commonly used by protesters. Another individual climbed on top of the trailer and attached themselves to an item on top of the trailer.

Via Giniw Collective/Facebook

Police say that at this point, several carloads of protesters arrived at the scene, and about 40 people began to protest.

As Hubbard County officers arrived on scene, they say they were required to provide traffic control “due to the traffic hazard that was caused by the now disabled semi tractor-trailer and the large number of protesters gathering on the side of the roadway.”

Deputies reportedly warned the protesters that they were in violation of Minnesota’s Public Nuisance and Unlawful Assembly laws and asked the crowd to disperse.

However, “after witnessing the protesters yelling vulgarities, being a traffic hazard, and refusing to leave,” officers began arresting people from the group.

In total, the Hubbard County Sheriff’s Office says that 31 people were arrested and booked on charges of Public Nuisance, Unlawful Assembly, and Disorderly Conduct.

The group Giniw Collective shared several photos from the June 15 protest activities on their Facebook page.