MINNEAPOLIS (WCCO) – Twenty-two people were arrested north of Palisade on Monday, as they opposed the replacement and building of the Line 3 Pipeline through northern Minnesota.

Enbridge Energy was given the green light to begin construction on the project in late November. The crude oil pipeline is expected to cost $2.6 billion.

Opponents of the pipeline have called themselves “water protectors” and have been trying to block construction. They say the pipeline threatens spillage and irreparable damage to waters the local tribes use to fish and harvest wild rice. In the time of COVID-19, the additional 4,000 workers who are expected to arrive in northern Minnesota could worsen the spread of the virus, impacting the communities along the Line 3 corridor.

MORE: Enbridge Line 3 Replacement Project Gets Final Approval From Minnesota Regulators

According to the Aitkin County Sheriff’s Office, demonstrators went into an area posted “No Trespassing” near the 59000 block of Great River Road in Jacobson on Monday afternoon. There was also a man who had been staying up in a tree platform since Dec. 4.

When they arrived, Sheriff Dan Guida saw someone fastened to a rope to block the right of way. Another line connected to it was secured above the man in the tree.

“The situation required a response to protect the person’s life as one mistake could have caused the apparatus, and individual in the tree, to fall 30 feet onto frozen ground,” said Guida.

He rode up in a bucket truck to the platform, and several people rushed from the woods to try to shut the truck down. They were arrested. The person in the tree said he was ready to come down and cooperate with law enforcement.

The 22 people were arrested and booked into the Aitkin County Adult Detention Center on probable cause trespassing and unlawful assembly. One person was booked on probable cause obstructing the legal process with force and fourth-degree assault.

Of the people arrested, Guida says that four were from northern Minnesota, 13 were from the Minneapolis-St. Paul metro area, and five were from out of state. None were from Aitkin County.