Three Duluth residents were cited for trespassing on Friday after occupying Enbridge's downtown office to demand that the company abandon its Line 3 replacement project.

Donna Howard, Mark Daniel Hakes and Michele Naar-Obed delivered a letter to Paul Eberth, director for the project intended to replace the existing pipeline crossing northern Minnesota from Alberta to Superior. They then refused to leave for almost two hours.

The two-page letter charged that Enbridge has been unlawfully stockpiling pipes intended for the project at 11 sites in northern Minnesota. It contended that Enbridge "fraudulently received permits to stockpile these illicit pipes."

When asked about that charge, an Enbridge spokeswoman responded that the company obtained its pipe yards before a September 2015 Minnesota Court of Appeals ruling that activated Minnesota Environmental Policy Act review.

"Statements to the alternative are simply not true and blatantly misrepresent the applicability of regulations at that time," spokeswoman Jennifer Smith wrote in an email.

Howard, Hakes and Naar-Obed arrived at the office shortly after noon. They left at 2 p.m. after a lengthy conference with Duluth police officers. They were backed by about 15 other people who met at the Central Hillside Community Center, fueled themselves with Little Caesars Pizza, then walked the three blocks to the Wieland Block, where they occupied the hallway outside the Enbridge offices. A security guard stood at the door, refusing to allow them to join Howard, Hakes and Naar-Obed inside. Seven Duluth police officers arrived a half-hour later, several stoically standing guard as protesters chanted, filmed video and occasionally knocked on office doors asking to see Eberth. Some looked through a glass window, partially covered with paper, as their colleagues met with other police officers in a conference room.

When the group formed at the community center, Jesse Peterson explained the trio's plans.

"They will not leave until they are arrested or until Enbridge agrees to meet their demands," he said.

Enbridge did not agree to the demands, and the three were not arrested. But in an email, Naar-Obed said she was satisfied with the results.

"We decided to not force them to carry us out," she wrote. "We would get the citation there or at the precinct. It would be the same essentially. The charge would increase if we resisted or fought them, and we didn't see the point in that. We will do what we can in the courtroom."

Naar-Obed called it "just the beginning of a long fight."

The protest came a day after the Minnesota Public Utilities Commission voted to instruct the state Department of Commerce and other agencies to refine three technical areas of the Line 3 project's final environmental impact statement, and to ensure a tribal cultural resource survey is complete before construction begins.

A final PUC decision on the pipeline is expected next year.