Four protesters were arrested Wednesday at an Enbridge pipeline work site in Superior.

Assistant Police Chief Matt Markon said that about 15 protesters assembled early Wednesday at the construction site along North 58th Street. All on-duty police officers were called to the scene. At one point, Markon said, at least six police officers and one Douglas County Sheriff’s Office deputy were on site.

One female was arrested for trespassing and resisting an officer, Markon said, and one male was arrested on Douglas County warrant related to an earlier protest in the Superior area. Two men who secured themselves to equipment also were arrested for trespassing, resisting arrest and bail jumping. After previous arrests, they had bail conditions of not interfering with Enbridge pipeline construction.

There was no damage done during the protest and no one was injured, police said. Police were on the scene for about six hours.

The protest was the latest in a series of actions taken against Enbridge's Line 3 project in Douglas County since late August, resulting in more than a dozen arrests. The protesters, who identify themselves as water protectors, have raised environmental concerns about the project.

The new pipeline would replace Enbridge's existing 50-year-old Line 3 that crosses northern Minnesota on its route from Alberta to Superior. While construction has started in both Canada and Wisconsin, the review process in Minnesota remains ongoing with a decision on whether to approve the pipeline expected next spring. The protests have called for the removal of Line 3.