Eighteen people were arrested at an immigration protest that shut down the Blue Line light-rail line Tuesday morning, forcing passengers to be shuttled on buses between 46th Street and Terminal 2 at the Minneapolis-St. Paul International Airport.

A dozen people demanding an end to deportations sat on the tracks, blocking the train near the Whipple Federal Building at Fort Snelling until they were arrested. After they were led away, six more sat down and were also arrested. All were charged with two misdemeanor counts of interference with transit and trespassing.

About 130 people in all were involved in the protest, organized by the Poor People's Campaign and the Minnesota Immigrant Rights Action Committee. Four of those arrested were ministers, three from Unitarian congregations.

Rob Eller-Isaacs, co-minister of Unity Church-Unitarian in St. Paul said the protest objective was "to draw attention to the immoral activities of ICE [U.S. Immigration and Customs Enforcement] and the bankrupt immigration policies of the United States. The deportations are breaking up families."

The demonstration was denounced Tuesday by state Rep. Nick Zerwas, R-Elk River, who authored legislation that would result in more serious charges for blocking thoroughfares. The latest effort was vetoed by Gov. Mark Dayton, who called the legislation's wording too vague.

"Today's protest is the latest example of why we need increased penalties for those who choose to put the public at risk by blocking highways, the airport, or access to transit," Zerwas said in a statement.

"Governor Dayton's veto of my bill allows for this unsafe, criminal behavior to continue with little more than a slap on the wrist for those who take part."

The Blue Line was shut down between 8:50 a.m. and 10:30 a.m., said Howie Padilla, a Metro Transit spokesman.

During the demonstration, protesters who were not arrested stood across a roadway that led to a parking lot adjacent to the light-rail station, forcing drivers to turn around.

"I need to go to work," commuter Cindy Smrcina angrily shouted out her car window as demonstrators walked up to the front of her car. "Why are you blocking us? It is selfish on your part. I have a job to get to."

Metro Transit police were generally gentle, asking older protesters if they wanted help getting to their feet as they were arrested for sitting on the tracks.

Among those charged was Ruthie Mhanga, 28, of Apple Valley, who is studying theology and said she has never been arrested in a protest before. "We need to be giving these people [who are facing deportation] the human dignity they deserve and the love and respect when they are facing hard times," she said.

Randy Furst • 612-673-4224 Twitter: @randyfurst